TY - JOUR. T1 - Reciprocal activation by cyclin-dependent kinases 2 and 7 is directed by substrate specificity determinants outside the T loop. AU - Garrett, S.. AU - Barton, W. A.. AU - Knights, R.. AU - Jin, P.. AU - Morgan, D. O.. AU - Fisher, R. P.. PY - 2001/1/1. Y1 - 2001/1/1. N2 - Cyclin-dependent kinase 7 (CDK7) is the catalytic subunit of the metazoan CDK-activating kinase (CAK), which activates CDKs, such as CDC2 and CDK2, through phosphorylation of a conserved threonine residue in the T loop. Full activation of CDK7 requires association with a positive regulatory subunit, cyclin H, and phosphorylation of a conserved threonine residue at position 170 in its own T loop. We show that threonine-170 of CDK7 is phosphorylated in vitro by its targets, CDC2 and CDK2, which also phosphorylate serine-164 in the CDK7 T loop, a site that perfectly matches their consensus phosphorylation site. In contrast, neither CDK4 nor CDK7 itself can phosphorylate the CDK7 T loop in vitro. The ability of CDC2 ...

TY - JOUR. T1 - switching On Enzyme Substrate Specificity Analysis with a Fluorescent Competitive Inhibitor. AU - Strom, Alexander. AU - Shah, Rachit. AU - Wagner, Carston R.. N1 - Funding Information: This work was funded by the University of Minnesota Foundation with additional support from the American Foundation for Pharmaceutical Education predoctoral fellowship awarded to A.S. Publisher Copyright: © 2021 American Chemical Society. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.. PY - 2021/2/16. Y1 - 2021/2/16. N2 - Enzymatically driven change to the spectroscopic properties of a chemical substrate or product has been a linchpin in the development of continuous enzyme kinetics assays. These assays inherently necessitate substrates or products that naturally comply with the constraints of the spectroscopic technique being used, or they require structural changes to the molecules involved to make them observable. Here we demonstrate a new analytical kinetics approach with ...

TY - JOUR. T1 - OXA-46, a new class D β-lactamase of narrow substrate specificity encoded by a blaVIM-1-containing integron from a Pseudomonas aeruginosa clinical isolate. AU - Giuliani, Francesco. AU - Docquier, Jean Denis. AU - Riccio, Maria Letizia. AU - Pagani, Laura. AU - Rossolini, Gian Maria. PY - 2005/5. Y1 - 2005/5. N2 - A novel OXA-type enzyme, named OXA-46, was found to be encoded by a gene cassette inserted into a class 1 integron from a multidrug-resistant Pseudomonas aeruginosa clinical isolate. The variable region of the integron also contained a blaVIM-1 metallo-β-lactamase cassette and a duplicated aacA4 aminoglycoside acetyltransferase cassette. OXA-46 belongs to the OXA-2 lineage of class D β-lactamases. It exhibits 78% sequence identity with OXA-2 and the highest similarity (around 92% identity) with another OXA-type enzyme detected in clinical isolates of Burkholderia cepacia and in unidentified bacteria from a wastewater plant. Expression of blaOXA-46 in Escherichia coli ...

What is enzyme substrate specificity? What are the importance of enzyme specificity? Classification of enzyme specificity, Different types of enzyme specificity: Bond specificity, Group specificity, Substrate specificity, Absolute Specificity, Optical or Stereo specificity, Geometrical specificity and Co-factor specificity. Learn more: Lecture Note in Specificity of Enzyme. You can DOWNLOAD the PPT by clicking on the download link below the preview…. ...

This invention comprises manufacture of photovoltaic cells by deposition of thin film photovoltaic junctions on metal foil substrates. The photovoltaic junctions may be heat treated if appropriate following deposition in a continuous fashion without deterioration of the metal support structure. In a separate operation, an interconnection substrate structure is provided, optionally in a continuous fashion. Multiple photovoltaic cells are then laminated to the interconnection substrate structure and conductive joining methods are employed to complete the array. In this way the interconnection substrate structure can be uniquely formulated from polymer-based materials employing optimal processing unique to polymeric materials. Furthermore, the photovoltaic junction and its metal foil support can be produced in bulk without the need to use the expensive and intricate material removal operations currently taught in the art to achieve series interconnections.

Use:. This mmp substrate can be used to assess activity of enzymes in the MMP family. The peptide sequence was described originally as a biosensor for MT1-MMP or MMP14 in Simultaneous visualization of protumorigenic Src and MT1-MMP activities with fluorescence resonance energy transfer. Ouyang M, et al. Cancer Res. 2010 Mar 15;70(6):2204-12. doi: 10.1158/0008-5472.CAN-09-3698″. It demonstrates reasonably strong activity against MT1-MMP or MMP14 and MMP3, but has the highest activity against MMP9 with specificity constants, kcat/Km (M-1s-1), ranging from approximately 103 to 106. See also our Product Sheets for its substrate specificity profile. This substrate is not processed by ADAM family members. Typically, the peptide is dissolved in DMSO to make a stock solution of about 10mM concentration. When used for in vitro assays, the substrate is often used at about 10uM concentration. Remember to keep the DMSO concentration in the final reaction at 1% or below, to avoid DMSO effects on the ...

Novel glycine oxidase (GlyOX) from Marinomonas mediterranea depends on cysteine tryptophilquinone (CTQ) and catalyzes the oxidative deamination of glycine to produce a glyoxylate, ammonia, and hydrogen peroxide. M. mediterranea GlyOX genes (goxA and goxB) were cloned and recombinant GlyOX was heterologously expressed by E. coli. The purification of recombinant GlyOX was carried out by metal affinity and DEAE-Toyopearl 650M column chromatographies. M. mediterranea GlyOX was homotetramic with a molecular mass of 76kDa and showed optimum activity around 30°C and at pH 5.0, and stability below 50°C and between pH 5.0 to 9.0. M. mediterranea GlyOX shows a strict substrate specificity toward glycine, and the Michaelis constant for glycine was 0.5mM. M. mediterranea GlyOX could determine the quantity of glycine in human serum and human blood plasma with high sensitivity. This study revealed the catalytic and structural properties of M. mediterranea GlyOX with high substrate specificity. ...

Background: Our understanding of how fungi evolved to develop a variety of ecological niches, is limited but of fundamental biological importance. Specifically, the evolution of enzymes affects how well species can adapt to new environmental conditions. Feruloyl esterases (FAEs) are enzymes able to hydrolyze the ester bonds linking ferulic acid to plant cell wall polysaccharides. The diversity of substrate specificities found in the FAE family shows that this family is old enough to have experienced the emergence and loss of many activities. Methodology/Principal Findings: In this study we evaluate the relative activity of FAEs against a variety of model substrates as a novel predictive tool for Ascomycota taxonomic classification. Our approach consists of two analytical steps; (1) an initial unsupervised analysis to cluster the FAEs substrate specificity data which were generated by cultivation of 34 Ascomycota strains and then an analysis of the produced enzyme cocktail against 10 substituted

AmpC BER is an extended substrate spectrum class C beta-lactamase with a two-amino-acid insertion in the R2 loop compared with AmpC EC2. The crystal structures of AmpC BER (S64A mutant) and AmpC EC2 were determined. Structural comparison of the two proteins revealed that the insertion increases the conformational flexibility of the R2 loop. Two citrate molecules originating from the crystallization solution were observed in the active site of the S64A mutant. One citrate molecule makes extensive interactions with active-site residues that are highly conserved among class C beta-lactamases, whereas the other one is weakly bound. Based on this structural observation, it is demonstrated that citrate, a primary metabolite that is widely used as a food additive, is a competitive inhibitor of two class C beta-lactamases (AmpC BER and CMY-10). Consequently, the data indicate enhancement of the flexibility of the R2 loop as an operative strategy for molecular evolution of extended-spectrum class C ...

Use:. This mmp substrate can be used to assess activity of MMP9 and MMP2. This mmp substrate has been used in enzymatic and cell based assays to assess activity of MMP9 and MMP2 since it is specific for this family of metalloproteinases. See our Product Sheets for its substrate specificity profile. Typically, the peptide is dissolved in DMSO to make a stock solution of about 10uM concentration. When used for in vitro assays, the substrate is often used at about 10mM concentration. Remember to keep the DMSO concentration in the final reaction at 1% or below, to avoid DMSO effects on the reaction, and remember to have an equivalent percentage of DMSO in the background wells. For use with the MMPs, the buffer should contain 50 mM Tris, pH 7.5, 150 mM NaCl, 2 mM CaCl2, 5 µM ZnSO4, and 0.01% Brij-35. Excitation and emission wavelengths are 485 and 530 nm respectively.. Molecular Weight:. 1423.4 g/mol. Purity:. Greater than 95% as assessed by HPLC and Mass Spectrometry.. Solubility:. 1 mg/ml in water ...

Vanillyl alcohol oxidase (VAO) and eugenol oxidase (EUGO) are flavin-dependent enzymes that catalyse the oxidation of para-substituted phenols. This makes them potentially interesting biocatalysts for the conversion of lignin-derived aromatic monomers to value-added compounds. To facilitate their biocatalytic exploitation, it is important to develop methods by which variants of the enzymes can be rapidly screened for increased activity towards substrates of interest. Here, we present the development of a screening assay for the substrate specificity of para-phenol oxidases based on the detection of hydrogen peroxide using the ferric-xylenol orange complex method. The assay was used to screen the activity of VAO and EUGO towards a set of twenty-four potential substrates. This led to the identification of 4-cyclopentylphenol as a new substrate of VAO and EUGO and 4-cyclohexylphenol as a new substrate of VAO. Screening of a small library of VAO and EUGO active-site variants for alterations in their

Phytaspase is a member of the plant subtilisin-like protease family, and is commonly distinguished from the other members by its unusual and extremely high specificity towards its substrates, which resembles that of the animal caspases. Similarly to the animal caspases, the phytaspase is a cell death promoting protease. The name phytaspase comes from phyto- (lat. for plant) and -aspase (aspartate-directed protease), similarly to caspases. The phytaspase displays a strict substrate specificity, which resembles that of the animal caspase-3. It recognizes a tetrapetide motive within a target protein and introduces a peptide bond break following an aspartate residue, which is crucial for the hydrolysis. Theoretical speculations, based on a 3D model predictions have been made, pointing to the histidine 331 of the phytaspase peptide chain, that might interact with the Asp in the target peptide and thereby guide the recognition. The phytaspase displays a structure, common to the subtilisin-like ...

0078] The coating composition according to the instant invention may be applied to a substrate. Exemplary suitable substrates include, but are not limited to, sheet, non-woven material, woven material, film, foams, and the like. Such substrate may comprise organic based materials, inorganic materials, and combinations thereof. The substrate may, for example, comprise a cellulose based material, a natural polymeric based material, a synthetic polymeric based material, a metal based material, a mineral based, and combinations thereof. The substrate may be porous, for example, micro-porous. The coating composition may be applied to the substrate via a conventional method for applying a coating composition. Such methods are generally known, and include, but are not limited to spraying, dipping, roll coating, blade coating, curtain coating, printing techniques such as flexography and rotogravure, size press, metered size press, screen coating, rod coating combinations thereof, and the like. The ...

The enzyme, characterized from the bacterium Bacillus subtilis, requires Mn2+ for activity. It shows strict substrate specificity toward L-arginine as the first (N-terminal) amino acid of the product. The second amino acid could be any standard protein-building amino acid except for L-proline ...

Galactokinase; Sugar-1-kinase with a strict substrate specificity for the alpha-anomeric configuration of D-galacturonic acid (D-GalA) and ATP. Involved in the biosynthesis of UDP-galacturonic acid (UDP-GalA) from the salvaged GalA that is released during growth- dependent cell wall restructuring (424 aa ...

SandeepWeb is a blog for research and reviews of different products that will help users to decide if the product is best for them or not.

SandeepWeb is a blog for research and reviews of different products that will help users to decide if the product is best for them or not.

Progression through S phase of the eukaryotic cell cycle is regulated by the action of the cyclin dependent protein kinase 2 (CDK2) in association with cyclin A. CDK2/cyclin A phosphorylates numerous substrates. Substrate specificity often employs a dual recognition strategy in which the sequence flanking the phospho-acceptor site (Ser.Pro.X.Arg/Lys) is recognized by CDK2, while the cyclin A component of the complex contains a hydrophobic site that binds Arg/Lys.X.Leu (RXL or KXL) substrate recruitment motifs. To determine additional sequence specificity motifs around the RXL sequence, we have performed X-ray crystallographic studies at 2.3 A resolution and isothermal calorimetry measurements on complexes of phospho-CDK2/cyclin A with a recruitment peptide derived from E2F1 and with shorter 11-mer peptides from p53, pRb, p27, E2F1, and p107. The results show that the cyclin recruitment site accommodates a second hydrophobic residue either immediately C-terminal or next adjacent to the ...

Progression through S phase of the eukaryotic cell cycle is regulated by the action of the cyclin dependent protein kinase 2 (CDK2) in association with cyclin A. CDK2/cyclin A phosphorylates numerous substrates. Substrate specificity often employs a dual recognition strategy in which the sequence flanking the phospho-acceptor site (Ser.Pro.X.Arg/Lys) is recognized by CDK2, while the cyclin A component of the complex contains a hydrophobic site that binds Arg/Lys.X.Leu (RXL or KXL) substrate recruitment motifs. To determine additional sequence specificity motifs around the RXL sequence, we have performed X-ray crystallographic studies at 2.3 A resolution and isothermal calorimetry measurements on complexes of phospho-CDK2/cyclin A with a recruitment peptide derived from E2F1 and with shorter 11-mer peptides from p53, pRb, p27, E2F1, and p107. The results show that the cyclin recruitment site accommodates a second hydrophobic residue either immediately C-terminal or next adjacent to the ...

Caspase-3 is a cysteine protease that hydrolyzes diverse intracellular proteins during programmed cell death (known as apoptosis). It has been a popular target for drug design against abnormal cell death for more than a decade. No approved caspase based drug, however, is available so far. Therefore, structural insights about the substrate recognition of caspase-3 are needed for the future development of caspase-3 based inhibitors and drugs. In this study, crystal structures of recombinant caspase-3 in complex with seven substrate analog inhibitors, including acetyl (Ac)-DEVD-aldehyde (Cho), Ac-DMQD-Cho, Ac-IEPD-Cho, Ac-YVAD-Cho, Ac-WEHD-Cho, Ac-VDVAD-Cho, and tert-butoxycarbonyl (Boc)-D-fluoromethylketone (Fmk), have been analyzed in combination with enzyme kinetic data and computational models. Seven crystal structures were determined at resolutions of 1.7-2.6Å. The binding conformation of each inhibitor residue at P1-P4 position was analyzed. The negative P1 aspartic acid side chain is exclusively

Identification of Crucial Amino Acids in Mouse Aldehyde Oxidase 3 That Determine Substrate Specificity. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

We are interested in the mechanistic and molecular relationships between catalytic activity, conformational changes and microenvironment of ABC transporters. P-glycoprotein (ABCB1, Pgp) is in the focus of our interest; we have currently extended our work to ABCG2 (BCRP) and plan to do similar studies on MRP1 (ABCC1). The members of the ABC superfamily of membrane transporters are involved in the regulation of the uptake into and distribution within our body of physiological substrates as well as various xenobiotics, drugs. Due to their wide substrate spectrum, a consequence of their preference for lipophylic compounds, they also play a critical role in the multidrug resistance phenomenon severely limiting therapeutical success in cancer. Our ambition is to understand the molecular details of their catalytic cycle and the intimate molecular interactions with their microenvironment, as well as to apply the knowledge obtained at the cell/molecule level in the context of the whole organism, in ...

Substrate specificity of hyaluronidases tested on polyacrylamide gel with incorporated chondroitin sulfate.Protein content per 2 µl dot is indicated in bracket

Has an unusual substrate specificity for synthetic organophosphate triesters and phosphorofluoridates. All of the phosphate triesters found to be substrates are synthetic compounds. The identity of any naturally occurring substrate for the enzyme is unknown. Has no detectable activity with phosphate monoesters or diesters and no activity as an esterase or protease. It catalyzes the hydrolysis of the insecticide paraoxon at a rate approaching the diffusion limit and thus appears to be optimally evolved for utilizing this synthetic substrate ...

The primary specificity residue of a substrate or an inhibitor, called the P1 residue, is responsible for the proper recognition by the cognate enzyme. This residue enters the S1 pocket of the enzyme and establishes contacts (up to 50%) inside the proteinase substrate cavity, strongly affecting its specificity. To analyze the influence on bovine α-chymotrypsin substrate activity, aromatic non-proteinogenic amino acid residues in position P1 with the sequence Ac-Phe-Ala-Thr-XAnb 5,2-NH2 were introduced: L-pyridyl alanine (Pal), 4-nitrophenylalanine - Phe(p-NO2), 4-aminophenylalanine - Phe(p- NH2), 4-carboxyphenylalanine Phe(p-COOH), 4-guanidine phenylalanine - Phe(p-guanidine), 4-methyloxycarbonylphenylalanine - Phe(p-COOMe), 4-cyanophenylalanine - Phe(p-CN), Phe, Tyr. The effect of the additional substituent at the phenyl ring of the Phe residue was investigated. All peptides contained an amide of 5-amino-2-nitrobenzoic acid, which served as a chromophore. Kinetic parameters (kcat, KM and ...

Many predicted (phospho)lipases are poorly characterized with regard to their substrate specificities and physiological functions. Here ...

To boost our understanding of Taspase1s substrate specificity we used our biosensor assay mixed with positional scanning mutagenesis

Motivation:In silico methods are being widely used for identifying substrates for various kinases and deciphering cell signaling networks. However, most of the available phosphorylation site prediction methods use motifs or profiles derived from a known data set of kinase substrates and hence, their applicability is limited to only those kinase families for which experimental substrate data is available. This prompted us to develop a novel multi-scale structure-based approach which does not require training using experimental substrate data.. Results:In this work, for the first time, we have used residue-based statistical pair potentials for scoring the binding energy of various substrate peptides in complex with kinases. Extensive benchmarking on Phospho.ELM data set indicate that our method outperforms other structure-based methods and has a prediction accuracy comparable to available sequence-based methods. We also demonstrate that the rank of the true substrate can be further improved, if ...

The RAS/MAPK pathway has been intensively studied [1-4], with constitutive activation of ERK1 and ERK2 found frequently in human cancer cells from a variety of tissues (e.g., lung, pancreas, colon, ovary, kidney, skin, and thyroid) [13]. Amplification, overexpression, or mutations in RTKs and genetic alterations in upstream components of the MAPK pathway, including KRAS, NRAS, HRAS, CRAF, BRAF, MEK1, and MEK2, alter cell signaling in tumors. In clinical practice and clinical trials, small molecules targeting RTKs or components in the MAPK cascade are used to treat cancer [1, 3, 4]. MEK1 and MEK2 are ideal targets; not only do they play a key role in tumor development and progression [3, 4], they have narrow substrate specificities and distinctive structural characteristics.. MEK activation through the MAPK signaling cascade is necessary for mammalian cell transformation, and constitutively active MEK mutants promote transformation of fibroblast cells [14, 15]. Furthermore, MEK inhibitors inhibit ...

within the GH-J clan. Moreover, besides the effect of substrate entrance on its own, we strongly suggest that a highly conserved arginine residue (in the RDP motif) rather than the previously proposed Tyr motif (not conserved) provides the proton to increase the pKa of the acid-base catalyst ...

Chaetoviridins constitute a large family of structurally related secondary metabolites isolated from Chaetomium fungi. To elucidate the biosynthesis pathway and understand how the chemical diversity of chaetoviridins is generated, gene deletion and in vitro characterization of the four post-PKS modifications enzymes were undertaken. CazL and CazP were identified to have substrate promiscuity that facilitates the formation of nonchlorinated analogues. In addition, enzymatic oxidation and reduction combined with spontaneous dehydration and lactonization of the intermediates further expand the chemical diversity ...

A method of forming a capacitive substrate in which at least one capacitive dielectric layer of material is screen or ink jet printed onto a conductor and the substrate is thereafter processed further, including the addition of thru-holes to couple selected elements within the substrate to form at least two capacitors as internal elements of the substrate. The capacitive substrate may be incorporated within a larger circuitized substrate, e.g., to form an electrical assembly. A method of making an information handling system including such substrates is also provided.

Thus, when a great deal of substrate is altered by an enzyme every minute, the reaction is said to be proceeding at a rapid rate.. In enzyme reaction rates, the rate depends on the CONCENTRATION of the enzyme and the CONCENTRATION of the substrate (CONCENTRATION rather than AMOUNT). Concentration refers to amount in a given volume of solution. As previously mentioned, it has been calculated that enzyme mediated reactions occur 1 x 109 times faster than the same reactions without enzymes.. In most enzyme reactions, enzyme concentration is small compared to the substrate concentration. Therefore, the rate of the reaction becomes proportional to the concentration of the enzyme. If the enzyme concentration is doubled, the reaction rate is doubled. At low substrate concentrations, the rate of the reaction is proportional to the substrate concentration, but at higher substrate concentrations the reaction rate is independent of substrate concentration. That is, further increase in the amount of ...

An apparatus includes a first substrate; and a second substrate coupled to the first substrate, characterized in that, to control formation of a segregated phase domain structure within a chemical reaction product by controlling an amount of a constituent of a precursor that is present per unit surface area, at least one member selected from the group consisting of the first substrate and the second substrate defines a substantially regularly periodically varying relief with respect to basal spatial location.

By Janine Mok, Philip M. Kim, Hugo Y. K. Lam, Stacy Piccirillo, Xiuqiong Zhou, Grace R. Jeschke, Douglas L. Sheridan, Sirlester A. Parker, Ved Desai, Miri Jwa, Elisabetta Cameroni, Hengyao Niu, Matthew Good, Attila Remenyi, Jia-Lin Nianhan Ma, Yi-Jun Sheu, Holly E. Sassi, Richelle Sopko, Clarence S. M. Chan, Claudio De Virgilio, Nancy M. Hollingsworth, Wendell A. Lim, David F. Stern, Bruce Stillman, Brenda J. Andrews, Mark B. Gerstein, Michael Snyder, Benjamin E. Turk. Science Signaling ...

Abstract Primary cilia are organelles necessary for proper implementation of developmental and homeostasis processes. To initiate their assembly, coordinated actions of multiple proteins are needed. Tau tubulin kinase 2 (TTBK2) is a key player in the cilium assembly pathway, controlling final step of cilia initiation. The function of TTBK2 in ciliogenesisis critically dependent on its kinase activity, however, precise mechanism of action of this kinase is so far incompletely understood, in part due to very limited information about its relevant substrates. In this study we identify CEP83, CEP89, CCDC92, Rabin8 and DVL3 as substrates of TTBK2 kinase activity. Further, we characterise a set of phosphosites of the newly identified substrates and CEP164, induced by TTBK2 in vitro and in vivo and show that TTBK2 preferentially phosphorylates examined substrates at intrinsically disordered regions (IDRs). Intriguingly, we further show that identified TTBK2 phosphosites and consensus sequence ...

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BioAssay record AID 1078669 submitted by ChEMBL: Inhibition of human P70S6K catalytic domain expressed in baculovirus assessed as substrate phosphorylation using fluorescence-labelled peptides as substrate at 70 uM after 90 mins by microfluidic peptide phosphorylation assay.

BioAssay record AID 1078796 submitted by ChEMBL: Inhibition of human FER catalytic domain expressed in baculovirus assessed as substrate phosphorylation using fluorescence-labelled peptides as substrate at 9 uM after 90 mins by microfluidic peptide phosphorylation assay.

Src Optimal Peptide Substrate 是一种高度特异性的 Src 底物。Src Optimal Peptide Substrate 可以用来检测 Src 活性。- 高纯度，全球文献引用。

Identifying the substrates of protein kinases to understand their modes of action has been undertaken by various approaches and remains an ongoing challenge

1UN4: Crystallographic Studies on Structural Features that Determine the Enzymatic Specificity and Potency of Human Angiogenin: Thr44, Thr80 and Residues 38-41

The more the enzyme of a particular substrate, the faster the rate of breakdown and therefore the more CO2 is produced. This will help me to test how much CO2 each substrate produces. Yeast can also respire aerobically and anerobically depending on the availability of O2.

At the atomic scale, we are interested in providing detailed three-dimensional information about the nature of complex metallocofactors to help understand how protein environment modulates reactivity. At the protein scale, we are interested in seeing how enzymes are constructed to control substrate access and specificity, and how they prevent loss of reactive intermediates or damage to expensive cofactors. At the largest scale, that of protein complexes, we want to know how proteins interact and how those interactions explain the observed behavior. Protein complexes are often large, have multiple distinct states, and can have large inter- and intrasubunit motions; therefore a single snapshot usually does not tell the entire story.. ...

TY - JOUR. T1 - Donor substrate promiscuity of bacterial β1-3-N-acetylglucosaminyltransferases and acceptor substrate flexibility of β1-4-galactosyltransferases. AU - Li, Yanhong. AU - Xue, Mengyang. AU - Sheng, Xue. AU - Yu, Hai. AU - Zeng, Jie. AU - Thon, Vireak. AU - Chen, Yi. AU - Muthana, Musleh M.. AU - Wang, Peng G.. AU - Chen, Xi. PY - 2016/4/15. Y1 - 2016/4/15. N2 - β1-3-N-Acetylglucosaminyltransferases (β3GlcNAcTs) and β1-4-galactosyltransferases (β4GalTs) have been broadly used in enzymatic synthesis of N-acetyllactosamine (LacNAc)-containing oligosaccharides and glycoconjugates including poly-LacNAc, and lacto-N-neotetraose (LNnT) found in the milk of human and other mammals. In order to explore oligosaccharides and derivatives that can be synthesized by the combination of β3GlcNAcTs and β4GalTs, donor substrate specificity studies of two bacterial β3GlcNAcTs from Helicobacter pylori (Hpβ3GlcNAcT) and Neisseria meningitidis (NmLgtA), respectively, using a library of 39 ...

Aniline dioxygenase is a multicomponent Rieske nonheme-iron dioxygenase enzyme isolated from Acinetobacter sp. strain YAA. Saturation mutagenesis of the substrate-binding pocket residues, which were identified using a homology model of the α subunit of the terminal dioxygenase (AtdA3), was used to probe the molecular determinants of AtdA substrate specificity. The V205A mutation widened the substrate specificity of aniline dioxygenase to include 2-isopropylaniline, for which the wild-type enzyme has no activity. The V205A mutation also made 2-isopropylaniline a better substrate for the enzyme than 2,4-dimethylaniline, a native substrate of the wild-type enzyme. The I248L mutation improved the activity of aniline dioxygenase against aniline and 2,4-dimethylaniline approximately 1.7-fold and 2.1-fold, respectively. Thus, it is shown that the α subunit of the terminal dioxygenase indeed plays a part in the substrate specificity as well as the activity of aniline dioxygenase. Interestingly, the ...

Aniline dioxygenase is a multicomponent Rieske nonheme-iron dioxygenase enzyme isolated from Acinetobacter sp. strain YAA. Saturation mutagenesis of the substrate-binding pocket residues, which were identified using a homology model of the α subunit of the terminal dioxygenase (AtdA3), was used to probe the molecular determinants of AtdA substrate specificity. The V205A mutation widened the substrate specificity of aniline dioxygenase to include 2-isopropylaniline, for which the wild-type enzyme has no activity. The V205A mutation also made 2-isopropylaniline a better substrate for the enzyme than 2,4-dimethylaniline, a native substrate of the wild-type enzyme. The I248L mutation improved the activity of aniline dioxygenase against aniline and 2,4-dimethylaniline approximately 1.7-fold and 2.1-fold, respectively. Thus, it is shown that the α subunit of the terminal dioxygenase indeed plays a part in the substrate specificity as well as the activity of aniline dioxygenase. Interestingly, the ...

TY - JOUR. T1 - Implication of substrate-assisted catalysis on improving lipase activity or enantioselectivity in organic solvents. AU - Tsai, Shau Wei. AU - Chen, Chun Chi. AU - Yang, Hung Shien. AU - Ng, I. Son. AU - Chen, Teh Liang. PY - 2006/8/1. Y1 - 2006/8/1. N2 - In comparison with the biocatalyst engineering and medium engineering approaches, very few examples have been reported on using the substrate engineering approach such as substrate-assisted catalysis (SAC) for naturally occurring or engineered lipases and serine proteases to improve the enzyme activity and enantioselectivity. By employing lipase-catalyzed hydrolysis of (R,S)-naproxen esters in water-saturated isooctane as the model system, we demonstrate the proton shuttle device to the leaving alcohol of the substrate as a new means of SAC to effectively improve the lipase activity or enantioselectivity. The result cannot only provide a strong evidence for the rate-limiting proton transfer for the bond-breaking of tetrahedron ...

TY - JOUR. T1 - Substrate specificity of bacterial oligosaccharyltransferase suggests a common transfer mechanism for the bacterial and eukaryotic systems. AU - Wacker, Michael. AU - Feldman, Mario F.. AU - Callewaert, Nico. AU - Kowarik, Michael. AU - Clarke, Bradley R.. AU - Pohl, Nicola L.. AU - Hernandez, Marcela. AU - Vines, Enrique D.. AU - Valvano, Miguel A.. AU - Whitfield, Chris. AU - Aebi, Markus. PY - 2006/5/2. Y1 - 2006/5/2. N2 - The PglB oligosaccharyltransferase (OTase) of Campylobacter jejuni can be functionally expressed in Escherichia coli, and its relaxed oligosaccharide substrate specificity allows the transfer of different glycans from the lipid carrier undecaprenyl pyrophosphate to an acceptor protein. To investigate the substrate specificity of PglB, we tested the transfer of a set of lipid-linked polysaccharides in E. coli and Salmonella enterica serovar Typhimurium. A hexose linked to the C-6 of the monosaccharide at the reducing end did not inhibit the transfer of the O ...

On December 12, 2016, Natural chemical biology reported a new research progress entitled Molecular Insights Into The Enzyme Promiscuity Of An Aromatic Prenyltransferase by Chinese Academy of Medical Sciences and Peking Union Medical College and Institute of Biophysics, Chinese Academy of Sciences. They reported a new type of aromatic prenyltransferase (AtaPT) that is cloned from microorganism with unprecedented substrate promiscuity, and discovered the relevant molecular mechanism. Traditionally, enzymes are considered to be specific towards their substrates; however, many enzymes show substrate promiscuity, which is different from natural substrates. The promiscuity of enzymes has draw peoples attraction, but the molecular mechanism is still unclear. The substitution reactions of prenyl moieties on natural compounds give rise to kinds of products with variety of structural types and bioactivities, which are important source for new drug discovery. The introduction of prenyl moieties into ...

The structural framework of cod liver alcohol dehydrogenase is similar to that of horse and human alcohol dehydrogenases. In contrast, the substrate pocket differs significantly, and main differences are located in three loops. Nevertheless, the substrate pocket is hydrophobic like that of the mammalian class I enzymes and has a similar topography in spite of many main-chain and side-chain differences. The structural framework of alcohol dehydrogenase is also present in a number of related enzymes like glucose dehydrogenase and quinone oxidoreductase. These enzymes have completely different substrate specificity, but also for these enzymes, the corresponding loops of the substrate pocket have significantly different structures. The domains of the two subunits in the crystals of the cod enzyme further differ by a rotation of the catalytic domains by about 6 degrees. In one subunit, they close around the coenzyme similarly as in coenzyme complexes of the horse enzyme, but form a more open cleft in ...

The opportunistic bacterium Proteus mirabilis secretes a metalloprotease, ZapA, considered to be one of its virulence factors due to its IgA-degrading activity. However, the substrate specificity of this enzyme has not yet been fully characterized. In the present study we used fluorescent peptides derived from bioactive peptides and the oxidized ß-chain of insulin to determine the enzyme specificity. The bradykinin- and dynorphin-derived peptides were cleaved at the single bonds Phe-Ser and Phe-Leu, with catalytic efficiencies of 291 and 13 mM/s, respectively. Besides confirming already published cleavage sites, a novel cleavage site was determined for the ß-chain of insulin (Val-Asn). Both the natural and the recombinant enzyme displayed the same broad specificity, demonstrated by the presence of hydrophobic, hydrophilic, charged and uncharged amino acid residues at the scissile bonds. Native IgA, however, was resistant to hydrolysis by ZapA ...

Viral papain-like cysteine protease (PLpro, NSP3) is essential for SARS-CoV-2 replication and represents a promising target for the development of antiviral drugs. Here, we used a combinatorial substrate library and performed comprehensive activity profiling of SARS-CoV-2 PLpro. On the scaffold of the best hits from positional scanning, we designed optimal fluorogenic substrates and irreversible inhibitors with a high degree of selectivity for SARS PLpro. We determined crystal structures of two of these inhibitors in complex with SARS-CoV-2 PLpro that reveals their inhibitory mechanisms and provides a molecular basis for the observed substrate specificity profiles. Last, we demonstrate that SARS-CoV-2 PLpro harbors deISGylating activity similar to SARSCoV-1 PLpro but its ability to hydrolyze K48-linked Ub chains is diminished, which our sequence and structure analysis provides a basis for. Together, this work has revealed the molecular rules governing PLpro substrate specificity and provides a ...

Recent research on the flavoenzyme D-amino acid oxidase from Rhodotorula gracilis (RgDAAO) has revealed new, intriguing properties of this catalyst and offers novel biotechnological applications. Among them, the reaction of RgDAAO has been exploited in the analytical determination of the D-amino acid content in biological samples. However, because the enzyme does not oxidize acidic D-amino acids, it cannot be used to detect the total amount of D-amino acids. We now present the results obtained using a random mutagenesis approach to produce RgDAAO mutants with a broader substrate specificity. The libraries of RgDAAO mutants were generated by error-prone PCR, expressed in BL21(DE3)pLysS Escherichia coli cells and screened for their ability to oxidize different substrates by means of an activity assay. Five random mutants that have a modified substrate specificity, more useful for the analytical determination of the entire content of D-amino acids than wild-type RgDAAO, have been isolated. With ...

H: Speaking of games, does your family have one of those old warped ping pong tables sitting in either your garage or basement? Yknow Taiwanese-style?. J: We did! Its not there anymore, but we had a ping pong table that got totally warped because we left it outside. In the Houston weather, with the humidity, the heat, and the rain -that thing got warped pretty quickly. So sad. So sad. There was a period of about a year -I think I was in fifth or sixth grade- where me and my friends pretty much did nothing but play ping pong for fun.. H: Ping pong is fun! If youre good at it. I suck. (laughs) Well, its so exciting that Ping Pong Playa is opening in several major cities this month! San Francisco Bay area, Los Angeles, New York, Seattle. Whats the plan for wider release?. J: Well, if it does well in the first few weekends -cross your fingers- then we will be able to expand out to other major metropolitan areas. But its definitely gonna require word-of-mouth spreading since we dont have the ...

Protein Kinase Substrate (PKS) Peptide Microarray - Comprehensive Service from LC Sciences,LC Sciences provides a comprehensive kinase analysis service utilizing high density protein kinase substrate (PKS) peptide microarrays synthesized on Paraflo microfluidic chips for proteomic scale kinase profiling, quantitative measurement of kinase kinetic activities, and drug discovery research.,biological,biology supply,biology supplies,biology product

atrazine chlorohydrolase: an atrazine-dechlorinating enzyme with restricted substrate specificity & contributes to the microbial hydrolysis of atrazine to hydroxyatrazine in soils & groundwater

TY - JOUR. T1 - Structural basis for substrate specificity in phosphate binding (β/α)8-barrels. T2 - D-allulose 6-phosphate 3-epimerase from Escherichia coli K-12. AU - Chan, Kui K.. AU - Fedorov, Alexander A.. AU - Fedorov, Elena V.. AU - Almo, Steven C.. AU - Gerlt, John A.. PY - 2008/9/9. Y1 - 2008/9/9. N2 - Enzymes that share the (β/α)8-barrel fold catalyze a diverse range of reactions. Many utilize phosphorylated substrates and share a conserved C-terminal (β/α)2-quarter barrel subdomain that provides a binding motif for the dianionic phosphate group. We recently reported functional and structural studies of D-ribulose 5-phosphate 3-epimerase (RPE) from Streptococcus pyogenes that catalyzes the equilibration of the pentulose 5-phosphates D-ribulose 5-phosphate and D-xylulose 5-phosphate in the pentose phosphate pathway [J. Akana, A. A. Fedorov, E. Fedorov, W. R. P. Novack, P. C. Babbitt, S. C. Almo, and J. A. Gerlt (2006) Biochemistry 45, 2493-2503]. We now report functional and ...

Looking for online definition of acceptor molecule in the Medical Dictionary? acceptor molecule explanation free. What is acceptor molecule? Meaning of acceptor molecule medical term. What does acceptor molecule mean?

Ping pong, also called table tennis, is a sport similar to tennis, usually played indoors on a table divided into two sides by a net, making use of small wooden rackets and a miniature ball. Ping pong originated in England in the late 19th century. Certain circles of the upper class were familiar with the traditional game of lawn tennis and sought to play the game on a smaller scale indoors. They entirely improvised their equipment: stacks of books acted as nets and cigar box lids sufficed as paddles. Balls were made of string, rubber, or sometimes cork. Game manufacturers quickly stepped in to market and sell equipment for the game and thus standardized it. The name for the game, ping pong, came from the sound that early paddles made when striking the ball; other popular names included whiff whaff and gossima By the early 20th century, the game was enjoyed in both Europe and the United States and is now a popular sport on an international level. The equipment in ping pong consists of small ...

Synonyms for Ping Pong Bone in Free Thesaurus. Antonyms for Ping Pong Bone. 16 synonyms for bone: cram, grind, os, osseous tissue, off-white, pearl, ivory, bone up, grind away, mug up, swot, swot up, cram, drum, get up, debone. What are synonyms for Ping Pong Bone?

An organic EL device includes a first substrate and a plurality of organic EL elements above a first portion of the first substrate. A first inorganic layer covers the plurality of organic EL elements. An active layer is above a second portion of the first substrate that is different than the first portion. The active layer comprises a material that is at least one of hygroscopic and oxidizable. A second inorganic layer covers the active layer. A second substrate is opposite the first substrate, with the plurality of organic EL elements being between the first and second substrates. A seal extends between the first and second substrates to define a sealed space between the first and second substrates. The second inorganic layer includes through-holes that expose the active layer to the sealed space that is defined by the first substrate, the second substrate, and the seal.

This thesis is focused on the development of methods for characterization and engineering of both proteases and affinity proteins. In addition, a prodrug concept for small affinity proteins is developed.. Two of the developed methods are for engineering and/or characterization of proteases. First, a method for substrate profiling and engineering of proteases was investigated (paper I). In this method, a protease and a reporter are co-expressed in E. coli. The reporter is comprised of an enzyme, which confers resistance to an antibiotic, fused to a substrate, and a degradation tag. In absence of site-specific proteolysis within the reporter, the degradation tag renders the entire reporter a substrate for the intracellular degradation machinery. Thus, by applying competitive growth in presence of the antibiotic, a substrate that is preferred by a model protease could be enriched relative to less efficiently hydrolyzed substrates. Then, an alternative method for substrate profiling was developed ...

Carboxylesterases hydrolyze numerous endogenous and foreign compounds with diverse structures. Humans and rodents express multiple forms of carboxylesterases, which share a high degree of sequence identity (∼70%). Alignment analyses locate in carboxylesterases several functional subsites such the catalytic triad as seen in acetylcholinesterase. The aim of this study was to determine among human and rodent carboxylesterases the immunorelatedness, overlapping substrate specificity, differential sensitivity to serine enzyme inhibitors, tissue distribution, and tumor-related expression. Six antibodies against whole carboxylesterases or synthetic peptides were tested for their reactivity toward 11 human or rodent recombinant carboxylesterases. The antibodies against whole proteins generally exhibited a broader cross-reactivity than the anti-peptide antibodies. All carboxylesterases hydrolyzed para-nitrophenylacetate and para-nitrophenylbutyrate. However, the relative activity varied markedly from ...

1KR2: Structure of Hhuman of Nicotinamide/Nicotinic Acid Mononucleotide Adenylyltransferase. Basis for the dual substrate specificity and activation of the oncolytic agent tiazofurin.

Structure of human nicotinamide/nicotinic acid mononucleotide adenylyltransferase. Basis for the dual substrate specificity and activation of the oncolytic agent tiazofurin

TY - JOUR. T1 - A novel auxin conjugate hydrolase from wheat with substrate specificity for longer side-chain auxin amide conjugates. AU - Campanella, James. AU - Olajide, Adebanke F.. AU - Magnus, Volker. AU - Ludwig-Müller, Jutta. PY - 2004/8/1. Y1 - 2004/8/1. N2 - This study investigates how the ILR1-like indole acetic acid (IAA) amidohydrolase family of genes has functionally evolved in the monocotyledonous species wheat (Triticum aestivum). An ortholog for the Arabidopsis IAR3 auxin amidohydrolase gene has been isolated from wheat (TaIAR3). The TaIAR3 protein hydrolyzes negligible levels of IAA-Ala and no other IAA amino acid conjugates tested, unlike its ortholog IAR3. Instead, TaIAR3 has low specificity for the ester conjugates IAA-Glc and IAA-myoinositol and high specificity for the conjugates of indole-3-butyric acid (IBA-Ala and IBA-Gly) and indole-3-propionic-acid (IPA-Ala) so far tested. TaIAR3 did not convert the methyl esters of the IBA conjugates with Ala and Gly. IBA and IBA ...

Altered sugar donor specificity and catalytic activity of pteridine glycosyltransferases by domain swapping or site-directed mutagenesis;kpubs;kpubs.org

Author: Jahnz, M. et al.; Genre: Journal Article; Published in Print: 2002-01; Title: FLP recombinase: Changing substrate specificity by evolutionary biotechnology

CLEAVITT, NATALIE L. Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9. - Disentangling moss species limitations: the role of substrate specificity. Substrate specificity has been pinpointed as key both in explaining plant species distributions and in differentiating types of plant rarity. The relative importance of substrate specificity to moss occurrence and rarity was evaluated for the rare moss species, Mielichhoferia macrocarpa, Mnium arizonicum and Didymodon johansenii and the taxonomically allied common species, Bryum pseudotriquetrum, Mnium spinulosum and Didymodon rigidulus var. icmadophilus, respectively. Substrate pH and percent organic matter were measured within five sites for each species. Sensitivity to these two substrate parameters was tested by a fragment regeneration experiment on native and non-native substrates. Evidence from field plot data and establishment experiments further resolved the role of substrate specificity in limiting M. ...

Get an answer for I have a question regarding how to find the isoelectric point (pI) of a peptide after amidation of the alpha-carboxyl group. The peptide I am working with is KQMP. I understand how to find the pI of the peptide before amidation given pk alpha-carboxyl = 2.0, pk alph-amino = 9.0, and pk epsilon-amino = 10.5. (pI=19.5/2) Upon amidation, I understand the amide group is not ionizable. Therefore, the alpha-amino group is deprotonated at pH=9, giving an equilibrium charge between +1 and +2, the epsilon-amino is deprotonated at pH=10.5 giving an equilibrium of charge between 0 and +1. There is no pKa remaining and no groups left to deprotonate. The net charge at pH=10.5 would be +1/2, so the pI would lie somewhere between a pH of 10.5 and 14. Is that all that can be determined, or is there a way to determine the pI exactly? and find homework help for other Biochemistry questions at eNotes

TY - JOUR. T1 - Substrate specificity of MATE1 and MATE2-K, human multidrug and toxin extrusions/H+-organic cation antiporters. AU - Tanihara, Yuko. AU - Masuda, Satohiro. AU - Sato, Tomoko. AU - Katsura, Toshiya. AU - Ogawa, Osamu. AU - Inui, Ken ichi. N1 - Funding Information: This work was supported in part by a Grant-in-Aid for Research on Advanced Medical Technology from the Ministry of Health, Labor, and Welfare of Japan; by the Japan Health Science Foundations Research on Health Sciences Focusing on Drug Innovation; by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Culture, and Sports of Japan; and by the 21st Century Center of Excellence program Knowledge Information Infrastructure for Genome Science. Y.T. was supported as a Research Assistant by Establishment of International Center of Excellence (COE) Formation for Genomic Analysis of Disease Model Animals with Multiple Genetic Alterations (COE program), Ministry of Education, Culture, Sports, ...

TY - JOUR UR - http://lib.ugent.be/catalog/pug01:787342 ID - pug01:787342 LA - eng TI - SitePredicting the cleavage of proteinase substrates PY - 2009 JO - (2009) TRENDS IN BIOCHEMICAL SCIENCES SN - 0968-0004 PB - LONDON ELSEVIER SCIENCE LONDON 2009 AU - Verspurten, Jelle WE14 801001990274 050696872871 AU - Gevaert, Kris GE07 801001024116 0000-0002-4237-0283 AU - Declercq, Wim WE14 801000707955 0000-0002-8218-2017 AU - Vandenabeele, Peter CA05 WE14 001979014511 AB - Proteinases are enzymes that play important roles invital cellular and extracellular processes by hydrolyticallycleaving peptide bonds in their protein substrates.This cleavage can be non-specific as part of degradationduring protein catabolism or highly specific as part ofproteolytic cascades and signal transduction events.Several web tools are available for predicting possiblecleavage sites in candidate substrates. Here, we compareexisting prediction tools with SitePrediction, anovel and user-friendly tool for identifying ...

BGs often show a complex kinetics, including inhibitory effects of substrate and activating effects of inhibitors. The substrate inhibition caused by the competing hydrolysis and transglycosylation to substrate reactions is well recognized [8-10]. This type of substrate inhibition is easily detected because of the breakdown of Michaelis-Menten saturation kinetics. Another inhibitory effect of substrate can be seen in nonproductive binding, which competes with the productive binding of substrate. Since, in this case, the Michaelis-Menten saturation kinetics holds, the effects of nonproductive binding are often overlooked. A kinetic peculiarity of many BGs is the activation of enzyme by inhibitor at low-to-moderate concentrations followed by inhibition at high concentrations. The most common explanation to this phenomenon is the transglycosylation to inhibitor, and, indeed, in many cases, the transglycosylation products are observed in reactions containing inhibitor [19, 26]. However, the ...

1. It has been claimed that, compared with plants grown without competition, plants competing for a common pool of soil-based resources overproduce roots at the expense of reproduction (known as the tragedy of the commons). However, experiments on this phenomenon have manipulated not only the presence/absence of neighbours, but also substrate volume. Restricted substrate volume can itself affect plant growth, possibly through chemical self-inhibition of root growth. We conducted an experiment with oats (Avena sativa) to examine whether the experimental design used in previous studies on the tragedy of the commons in root competition might have confounded the effects of detection of neighbours and substrate volume. 2 .Six treatments combined two factors, namely the presence or absence of activated carbon, and either the presence of a plastic or a mesh partition, or the absence of a partition, between two plants in a pot. Activated carbon was used to adsorb root exudates and reduce their potential ...

In competitive inhibition, an inhibitor that resembles the normal substrate binds to the enzyme, usually at the active site, and prevents the substrate from binding.[8] At any given moment, the enzyme may be bound to the inhibitor, the substrate, or neither, but it cannot bind both at the same time. During competitive inhibition, the inhibitor and substrate compete for the active site. The active site is a region on an enzyme which a particular protein or substrate can bind to. The active site will only allow one of the two complexes to bind to the site therefore either allowing for a reaction to occur or yielding it. In competitive inhibition the inhibitor resembles the substrate therefore taking its place and binding to the active site of an enzyme. Increasing the substrate concentration would diminish the competition for the substrate to properly bind to the active site and allow a reaction to occur.[3] When the substrate is of higher concentration than that of the competitive inhibitor, it ...

As enzymes have evolved to bind their substrates tightly, and most reversible inhibitors bind in the active site of enzymes, it is unsurprising that some of these inhibitors are strikingly similar in structure to the substrates of their targets. Inhibitors of DHFR are prominent examples[2][3][1]. Other example of these substrate mimics are the protease inhibitors, a very successful class of antiretroviral drugs used to treat HIV.[24] The structure of ritonavir, a protease inhibitor based on a peptide and containing three peptide bonds, is shown on the right. As this drug resembles the protein that is the substrate of the HIV protease, it competes with this substrate in the enzymes active site. Enzyme inhibitors are often designed to mimic the transition state or intermediate of an enzyme-catalyzed reaction. This ensures that the inhibitor exploits the transition state stabilising effect of the enzyme, resulting in a better binding affinity (lower Ki) than substrate-based designs. An example of ...

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Many inhibitors affect enzyme activity • Competitive inhibition - inhibitor competes for the active sites on enzyme with the substrate • Non-competitive inhibition - inhibitor binds to an allosteric site and alters the active site configuration of the enzyme • Feedback inhibition - enzyme activity is inhibited by the end product (A enzyme-1 B enzyme-2 C enzyme-3 D) - here enzyme-1 may be inhibited by product D • Feedback inhibition regulates ATP, amino acid, numcleotide and vitamin synthesis Mechanism of enzyme action • Substrate specifically binds to the active site on the surface of the enzyme and as a consequence enzyme-substrate complex is formed - can result in change of structure of the enzyme • Substrate is transformed into product by - Rearrangement of existing atoms - Breakdown of substrate molecules - Combining with other substrate molecules • Resultant products do not fit the active site and thus are released and the enzyme site becomes free for ...

Whereas enzymes are widely renowned for the exquisite specificity, we showed that enzymes also have low levels of catalysis for alternative reactions, an observation we described as catalytic promiscuity.. Catalytic promiscuity has been a key driver in the evolution of new enzymes, providing a head start and selective advantage for enzymes already possessing a low level of advantageous activity.. Catalytic promiscuity provides a powerful tool for addressing evolutionary and mechanistic questions. We are exploiting catalytic promiscuity across an enzyme superfamily to gain an understanding of the fundamental underpinnings of catalysis. Unlike traditional site-directed mutagenesis, experiments that are often limited to studying a single reaction catalyzed by an individual enzyme, we are using a comparative approach to ask not simply what the consequence is of removing a particular side chain, but how that removal and change in the side chain affects normal and promiscuous reactions. Because the ...

EC 1.2.1.19. Accepted name: aminobutyraldehyde dehydrogenase. Reaction: 4-aminobutanal + NAD+ + H2O = 4-aminobutanoate + NADH + 2 H+. For diagram click here.. Glossary: 4-aminobutanoate = γ-aminobutyrate = GABA. Other name(s): ABAL dehydrogenase; 4-aminobutyraldehyde dehydrogenase; 4-aminobutanal dehydrogenase; γ-aminobutyraldehyde dehydroganase; 1-pyrroline dehydrogenase; ABALDH; YdcW; γ-guanidinobutyraldehyde dehydrogenase (ambiguous). Systematic name: 4-aminobutanal:NAD+ 1-oxidoreductase. Comments: The enzyme from some species exhibits broad substrate specificity and has a marked preference for straight-chain aldehydes (up to 7 carbon atoms) as substrates [9]. The plant enzyme also acts on 4-guanidinobutanal (cf. EC 1.2.1.54 γ-guanidinobutyraldehyde dehydrogenase). As 1-pyrroline and 4-aminobutanal are in equilibrium and can be interconverted spontaneously, 1-pyrroline may act as the starting substrate. The enzyme forms part of the arginine-catabolism pathway [8] and belongs in the ...

Affinity chromatography is a convective analytical or preparative technique which is used to separate components in a mixture of chemical compounds based on differences in their ability to bind to particular substrate. In affinity chromatography, a substrate is immobilized on the stationary phase media which is packed into a chromatography column. Mixtures containing the analyte are injected onto the column, where any components of the mixture with a propensity to bind to the substrate will become attached to the stationary phase and all other components of the mixture will simply run through the column. Attached particles can then be eluted from the column by adding a compound which disrupts the interaction between the substrate and the stationary phase. Commonly-used substrate ligands include metal-ions, antibodies, or small molecules such as ATP.. With the recent focus on recombinant proteins and antibodies in biomedical research, affinity chromatography has emerged as an important technique ...

The invention relates to a simple and cost-effective method for aligning substrates. In order to achieve this, the invention provides a device for aligning disc-shaped substrates, in particular semiconductor wafers, comprising an alignment detection unit, at least one first support for receiving the substrate, which forms an oblique plane in relation to the horizontal, a stop against which the substrate can be displaced as a result of the oblique angle and a rotational device for rotating the substrate. The invention also relates to a method for aligning disc-shaped substrates, in particular semiconductor wafers, comprising the following steps: displacement of the substrate into an oblique position in relation to the horizontal, in which the substrate is held on a support which forms a tilted plane in relation to the horizontal and lies against a stop as a result of the oblique angle; rotation of the substrate into a predefined rotational position; and monitoring of the rotational position using a

Dang, Q. D., and Di Cera, E. (1997) Nat. Biotechnol. 15, 891-895; and Le Bonniec, B. F., MacGillivray, R. T., and Esmon, C. T. (1991) J. Biol. Chem. 266, 13796-13803). Optimal binding interactions witin thrombin occur only if these tripeptide substrates contain an amino acid residue in the (D)-configuration, such as (d)Phe at P3 (Blomback, B., Blomback, M., Olsson, P., Svendsen, L., and Aberg, G. (1969) Scand. J. Clin. Lab Invest SuppI 107, 59-61), which mimics the natural Pgresidue in FpA (Ni, F., Meinwald, Y. C, Vasquez, M., and Scheraga, H. A. (1989) Biochemistry 28, 3094-3105; Stubbs, M. T., Oschkinat, H., Mayr, I., Huber, R., Angliker, H., Stone, S. R., and Bode, W. (1992) Eur. J. Biochem. 206, 187-195; and Martin, P. D., Robertson, W., Turk, D., Huber, R., Bode, W., and Edwards, B. F. (1992) J. Biol. Chem. 267, 7911-7920). However, these minimalistic peptide substrates probe only the active site apparatus of thrombin and related binding events, which were found to be mildly sensitive to ...

The capabilities of molecular docking to identify substrates and non-substrates were improved by using the method of substrate-imprinted docking. Docking 2- to 8-MDBs into substrate-imprinted CRL structures led to 58 productive poses (Table 3). The two structures with the displaced histidine (1LPN, 1LPP) did not provide any productive poses, as was already observed for the conventional docking. Thus, the identification of these esters as substrates was improved by substrate-imprinted docking to an accuracy of 59%, compared to the accuracy of 42% that was achieved with conventional docking. In contrast, substrate-imprinted docking was not able to identify enantioselectivities in the case of CRL and MDBs. When 2-HOB was docked into substrate-imprinted CRL structures, four productive poses could be found for the (R)-enantiomer and five for the (S)-enantiomer (Table 4). When using substrate-imprinted BCL structures, six productive poses were found for (R)-2-HOB and six productive poses were found ...

Shop Neurolysin ELISA Kit, Recombinant Protein and Neurolysin Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.

The Michaelis Constant, KM is very important in determining enzyme-substrate interaction. This value of enzyme range widely and often dependent on environmental conditions such as pH, temperature, and ionic strength. The KM is able to detect two factors: One is the concentration of substrate when the reaction velocity is half that of the maximal velocity; thus, the Michaelis constant measures the concentration of substrate required for a significant catalysis to take place. Secondly, it is, in some cases, able to detect the strength of the enzyme-substrate complex (ES). When, and only when k2 ,, k-1, High KM indicates weak binding and low KM indicates strong binding. Under this special circumstance, KM is equal to the dissociation constant. Only then can the KM be used as a measurement of the strength of the ES complex. There are cases where changes in the Michaelis constant are observed as is the case with inhibitors such as competitive, uncompetitive and noncompetitive inhibitors. In ...

Ken Houk has produced a very nice minireview on bifurcations in organic reactions.1 This article is a great introduction to a topic that has broad implication for mechanistic concepts. Bifurcations result when a valley-ridge inflection point occurs on or near the intrinsic reaction coordinate. This inflection point allows trajectories to split into neighboring basins (to proceed to different products) without crossing a second transition state. In the examples discussed, the reactant crosses a single transition state and then leads to two different products. This is the so-called two-step no intermediate process.. I discuss the implications of these kinds of potential energy surfaces, and other ones of a pathological nature, in the last chapter of my book. Very interesting reaction dynamics often are the result, leading to a mechanistic understanding far from the ordinary!. ...

A developing apparatus for developing a photoresist-coated substrate comprises a spin chuck having a supporting surface smaller in size than the substrate and adapted to be spin-driven with the photoresist-coated substrate surface held upward, a cup surrounding the spin chuck, a developing solution nozzle for applying a developing solution on the photoresist-coated substrate held on the spin chuck, a first washing solution nozzle for applying a washing solution to the photoresist-coated surface of the substrate held on the spin chuck, a second washing solution nozzle for applying the washing solution to a rear surface of the substrate on the spin chuck, a liquid seal ring mounted substantially coaxial with the spin chuck and having a diameter greater than the supporting surface of the spin chuck and smaller than the substrate, and a liquid film forming section provided on an upper end of the liquid seal ring and located near and opposite a peripheral edge portion of a rear surface of the substrate on