• Heat Denaturation
  • Radioimmunoassay and heat denaturation enzyme assay for the detection of Tay-sachs heterozygotes during pregnancy. (biomedsearch.com)
  • HEX I dose not increase in leucocytes, tears and other body tissues but because of technical difficulties in these assays we examined the feasibility of using a radioimmunoassay for HEX A. By univariate analysis, the heat denaturation assay gave a lower cost of misclassification for non-pregnant normals while RIA did so for pregnant normals. (biomedsearch.com)
  • Bayesian analysis of bivariate gaussian density functions for heat denaturation and for radioimmunoassay of HEX isoenzymes was employed to calculate misclassification frequencies. (biomedsearch.com)
  • Among the parameters examined, HEX A measured by RIA and % HEX A by heat-denaturation assay were the two having the best discriminatory power. (biomedsearch.com)
  • hydrophobic
  • This cold denaturation phenomenon is usually linked to the temperature-dependent hydrophobic driving force for protein folding. (lu.se)
  • Once this post-translational modification process has been completed, the protein begins to fold (sometimes spontaneously and sometimes with enzymatic assistance), curling up on itself so that hydrophobic elements of the protein are buried deep inside the structure and hydrophilic elements end up on the outside. (wikipedia.org)
  • In the case of protein folding, the hydrophobic effect is important to understanding the structure of proteins that have hydrophobic amino acids (such as glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan and methionine) clustered together within the protein. (wikipedia.org)
  • Structures of water-soluble proteins have a hydrophobic core in which side chains are buried from water, which stabilizes the folded state. (wikipedia.org)
  • Minimizing the number of hydrophobic side chains exposed to water is the principal driving force behind the folding process, although formation of hydrogen bonds within the protein also stabilizes protein structure. (wikipedia.org)
  • Column chromatography with a hydrophobic stationary phase such as phenyl-sepharose will cause more hydrophobic proteins to travel more slowly, while less hydrophobic ones elute from the column sooner. (wikipedia.org)
  • Biomolecules, particularly proteins, can be immobilized simply on an unmodified substrate surface through hydrophobic or electrostatic interactions. (wikipedia.org)
  • Although later data demonstrated that this original model for the structure of globular proteins needed to be amended, several elements of the cyclol model were verified, such as the cyclol reaction itself and the hypothesis that hydrophobic interactions are chiefly responsible for protein folding. (wikipedia.org)
  • chemical
  • Virtually all the complex chemical functions of the living cell are performed by protein-based catalysts called enzymes. (wikibooks.org)
  • In addition to their catalytic functions, proteins can transmit and commute signals from the extracellular environment, duplicate genetic information, assist in transforming the energy in light and chemicals with astonishing efficiency, convert chemical energy into mechanical work, and carry molecules between cell compartments. (wikibooks.org)
  • A series of chemical treatments then enables deposition of the protein in the desired pattern upon the material underneath the photomask. (wikipedia.org)
  • Chemical modification of surfaces has been successfully applied in several instances to immobilize proteins in order to obtain valuable information. (wikipedia.org)
  • By the mid-1930s, analytical ultracentrifugation studies by Theodor Svedberg had shown that proteins had a well-defined chemical structure, and were not aggregations of small molecules. (wikipedia.org)
  • The chemical structure of proteins was still under debate at that time. (wikipedia.org)
  • Hence, alternative chemical models of proteins were considered, such as the diketopiperazine hypothesis of Emil Abderhalden. (wikipedia.org)
  • Tim Anson and Alfred Mirsky had shown that denaturation was a reversible, two-state process that results in many chemical groups becoming available for chemical reactions, including cleavage by enzymes. (wikipedia.org)
  • Nevertheless, protein scientists could not exclude the possibility that denaturation corresponded to a chemical change in the protein structure, a hypothesis that was considered a (distant) possibility until the 1950s. (wikipedia.org)
  • tertiary structure
  • Tertiary structure denaturation involves the disruption of: Covalent interactions between amino acid side-chains (such as disulfide bridges between cysteine groups) Non-covalent dipole-dipole interactions between polar amino acid side-chains (and the surrounding solvent) Van der Waals (induced dipole) interactions between nonpolar amino acid side-chains. (wikipedia.org)
  • Finally, the hypothesis assumes that globular proteins have a tertiary structure corresponding to Platonic solids and semiregular polyhedra formed of cyclol fabrics with no free edges. (wikipedia.org)
  • coagulation
  • 3 Preface The present master thesis, The effect of heating processes on milk whey protein denaturation and rennet coagulation properties of 60 ECTS was part of the education Molecular Nutrition and Food Technology at Aarhus University and was performed in the period October 2013 to October2014. (docplayer.net)
  • Skim milk with various contents of whey proteins and caseins were heat treated using three different heating processes, namely Plate Heat Exchanger (PHE), Tubular Heat Exchanger (THE) and Direct Steam Injection (DSI) to provide further insight into how heat treatment affects whey protein denaturation and rennet coagulation. (docplayer.net)
  • The milk samples were analysed on liquid chromatography (LC) to analyse the degree of whey protein denaturation, while rennet coagulation analysis were made with ReoRox rheometry. (docplayer.net)
  • Milk with reduced whey protein content showed improved rennet coagulation properties for all heating methods compared to skim milk. (docplayer.net)
  • Increasing the casein level and reducing the whey protein content gave further improvements of rennet coagulation properties. (docplayer.net)
  • The process of protein denaturation (as distinguished from coagulation) had been discovered in 1910 by Harriette Chick and Charles Martin, but its nature was still mysterious. (wikipedia.org)
  • Enzymes
  • Protein enzymes should not be confused with RNA-based enzymes (also called ribozymes), a group of macromolecules that perform functions similar to protein enzymes. (wikibooks.org)
  • Further doubts about the polypeptide nature of proteins arose because some enzymes were observed to cleave proteins but not peptides, whereas other enzymes cleave peptides but not folded proteins. (wikipedia.org)
  • peptides
  • Terminal amine isotopic labeling of substrates (TAILS) is a method in quantitative proteomics that identifies the protein content of samples based on N-terminal fragments of each protein (N-terminal peptides) and detects differences in protein abundance among samples. (wikipedia.org)
  • Like other methods based on N-terminal peptides, this assay uses trypsin to break proteins into fragments and separates the N-terminal peptides (the fragments containing the N-termini of the original proteins) from the other fragments (internal tryptic peptides). (wikipedia.org)
  • Alternative methods that rely on the free amino group of the N-terminus to identify the N-terminal peptides cannot detect some N-termini because they are "naturally blocked" (i.e. the natural protein does not have a free amino group). (wikipedia.org)
  • However, it identifies ~ 50% of proteins by two or more different and unique peptides (one of the original mature N-terminus and/or one or more neo-N-terminal peptide via cleavage site) that do not represent independent biological events thus cannot be averaged for quantification[clarification needed]. (wikipedia.org)
  • The labeled N-termini of the original proteins remain blocked, while the new internal tryptic peptides have a free N-terminus. (wikipedia.org)
  • However, no alternative model had yet explained why proteins yield only amino acids and peptides upon hydrolysis and proteolysis. (wikipedia.org)
  • metabolism
  • Proteins don't act as fundamental energy reserves in most organisms, as their metabolism is slower and inefficient compared to sugars or lipids. (wikibooks.org)
  • substrates
  • The TAILS method has a number of applications including the identification of new substrates and proteases (including those that have an unknown and broad specificity) and as a way to define the termini of proteins that enables protein annotation. (wikipedia.org)
  • Quantitative
  • A quantitative study of the effects of chaotropic agents, surfactants, and solvents on the digestion efficiency of human plasma proteins by trypsin," Journal of Proteome Research , vol. 9, no. 10, pp. 5422-5437, 2010. (hindawi.com)
  • Other related techniques include dot blot analysis, quantitative dot blot, immunohistochemistry, and immunocytochemistry where antibodies are used to detect proteins in tissues and cells by immunostaining, and enzyme-linked immunosorbent assay (ELISA). (wikipedia.org)
  • A semi-quantitative estimation of a protein can be derived from the size and color intensity of a protein band on the blot membrane. (wikipedia.org)
  • temperature
  • Unlike most ordered molecular systems, globular proteins exhibit a temperature of maximum stability, implying that the structure can be disrupted by cooling. (lu.se)
  • Here, we use water−17O spin relaxation to monitor the hydration dynamics of the proteins BPTI, ubiquitin, apomyoglobin, and β-lactoglobulin in aqueous solution from room temperature down to −35 °C. To access this temperature range without ice formation, we contained the protein solution in nonperturbing. (lu.se)
  • Our results also suggest that the reported cold denaturation at −20 °C of ubiquitin encapsulated in reverse micelles is caused by the low water content rather than by the low temperature. (lu.se)
  • This temperature is higher than the critical level for protein denaturation in the body. (wikipedia.org)
  • Immediately after exposure to high temperature stress-related proteins are expressed as stress defense strategy of the cell. (wikipedia.org)
  • guanidinium chloride
  • Guanidinium chloride is a strong chaotrope and one of the strongest denaturants used in physiochemical studies of protein folding. (wikipedia.org)
  • At high concentrations of guanidinium chloride (e.g., 6 M), proteins lose their ordered structure, and they tend to become randomly coiled, i.e. they do not contain any residual structure. (wikipedia.org)
  • We also measure mRFP deactivation in solutions containing denaturants (guanidinium chloride or urea) or stabilizing co-solutes (glycerol or sucrose) frequently encountered in many protein formulations to test whether hydration of these co-solutes can be used to indicate their relative effects on protein kinetic stability. (biomedsearch.com)
  • interactions
  • Yet, despite the key role played by protein−water interactions, hydration changes during cold denaturation have not been investigated experimentally. (lu.se)
  • A protein microarray (or protein chip) is a high-throughput method used to track the interactions and activities of proteins, and to determine their function, and determining function on a large scale. (wikipedia.org)
  • urea
  • Trimethylamine oxide also serves to counteract the protein-destabilizing tendencies of urea and pressure. (wikipedia.org)
  • Cytochrome
  • The denaturation of Thermus thermophilus cytochrome c-552 by acid, guanidine hydrochloride, and heat was studied by measuring the changes in absorption and circular dichroism. (biomedsearch.com)
  • structural
  • It is theorized that prions may be able to act as a structural template for other chemically (but not structurally) identical proteins, but they can't function as a native template for protein synthesis de novo . (wikibooks.org)
  • Since all structural levels of the protein determine its function, the protein can no longer perform its function once it has been denatured. (wikipedia.org)
  • concentrations
  • This N 0.59 scaling arises because denatured proteins expand to make favorable contacts with the surrounding solvent, implying that high concentrations of denaturants are good solvents for generic proteins. (pnas.org)
  • At protein concentrations below 0.5 mg/ml, the data from sedimentation studies can be fitted to a single isodesmic model. (biomedsearch.com)
  • By also applying a dilution series of a purified protein with known concentrations, a more precise estimate of the quantity can be obtained. (wikipedia.org)
  • But hydrogen bonds, which play a big part in folding, are rather weak, and it doesn't take much heat, acidity, varying salt concentrations, or other stress to break some and form others, denaturing the protein. (wikipedia.org)
  • polypeptide
  • The western blot method is composed of a gel electrophoresis to separate native proteins by 3-D structure or denatured proteins by the length of the polypeptide, followed by an electrophoretic transfer onto a membrane (mostly PVDF or Nitrocellulose) and an immunostaining procedure to visualize a certain protein on the blot membrane. (wikipedia.org)
  • analysis
  • Download PDF ' analysis-of-proteins-pdf ' for free at This Site. (pdf-engines.com)
  • P. Carlson, D. M. Smalley, and R. J. van Beneden, "Proteomic analysis of arsenic-exposed zebrafish ( Danio rerio ) identifies altered expression in proteins involved in fibrosis and lipid uptake in a gender-specific manner," Toxicological Sciences , vol. 134, no. 1, pp. 83-91, 2013. (hindawi.com)
  • Comparison of SDS- and methanol-assisted protein solubilization and digestion methods for Escherichia coli membrane proteome analysis by 2-D LC-MS/MS," Proteomics , vol. 7, no. 4, pp. 484-493, 2007. (hindawi.com)
  • Protein microarrays replace traditional proteomics techniques such as 2D gel electrophoresis or chromatography, which were time consuming, labor-intensive and ill-suited for the analysis of low abundant proteins. (wikipedia.org)
  • Nanoscale analysis of proteins using atomic force microscopy (AFM) requires surfaces with well-defined topologies and chemistries for many experimental techniques. (wikipedia.org)
  • aggregates
  • THE was found to result in a higher degree of large whey protein and κ-casein complexes, while a higher proportion of smaller whey protein aggregates were found when heating using PHE. (docplayer.net)
  • structures
  • The folding of the protein, caused by structures and attractions between different parts of the protein, exposes or hides its different regions, determining how it reacts to its environment. (reference.com)
  • stability
  • Cation and strong co-solute effects on protein kinetic stability. (biomedsearch.com)
  • Here, we test the influence of cations on protein kinetic stability by observing deactivation of mRFP (monomeric red fluorescent protein) in ammonium, caesium and chloride salt solutions, and we find that mRFP deactivation does not depend on cation hydration. (biomedsearch.com)
  • Salts
  • We have previously found that the deactivating effects of salts on proteins can be correlated to an indicator of ion hydration, the B-viscosity coefficient of the anion in solution. (biomedsearch.com)
  • Cast formation is pronounced in environments favoring protein denaturation and precipitation (low flow, concentrated salts, low pH). (wikipedia.org)
  • functions
  • The chosen solid surface is then covered with a coating that must serve the simultaneous functions of immobilising the protein, preventing its denaturation, orienting it in the appropriate direction so that its binding sites are accessible, and providing a hydrophilic environment in which the binding reaction can occur. (wikipedia.org)
  • Abstract
  • 5 Abstract Whey protein denaturation as a cause of heat treatment has been investigated by various authors with the study by Dannenberg and Kessler (1988) being the most acknowledged. (docplayer.net)