... is regulated by both allosteric control and by phosphorylation.. Hormones such as epinephrine, insulin and glucagon regulate glycogen phosphorylase using second messenger amplification systems that are linked to G proteins. Glucagon activates adenylate cyclase through a seven transmembrane receptor coupled to Gs which, in turn, activates adenylate cyclase to increase intracellular concentrations of cAMP. cAMP binds to and releases an active form of protein kinase A (PKA). Next, PKA phosphorylates phosphorylase kinase, which, in turn, phosphorylates glycogen phosphorylase b, transforming it into the active glycogen phosphorylase a. This phosphorylation is added onto the glycogen phosphorylase b serine 14. In the liver, glucagon activates another G-protein-linked receptor that triggers a different cascade, resulting in the activation of Phospholipase C (PLC). PLC indirectly causes the release of calcium from the ...
... (abbreviation: GPBB) is an isoenzyme of glycogen phosphorylase. This isoform of the enzyme exists in cardiac (heart) and brain tissue. The enzyme is one of the "new cardiac markers" which are discussed to improve early diagnosis in acute coronary syndrome. A rapid rise in blood levels can be seen in myocardial infarction and unstable angina. Other enzymes related to glycogen phosphorylase are abbreviated as GPLL (liver) and GPMM (muscle). Apple FS, Wu AH, Mair J, et al. (May 2005). "Future biomarkers for detection of ischemia and risk stratification in acute coronary syndrome". Clin. Chem. 51 (5): 810-24. doi:10.1373/clinchem.2004.046292. PMID 15774573. Peetz D, Post F, Schinzel H, et al. (2005). "Glycogen phosphorylase BB in acute coronary syndromes". Clin. Chem. Lab. Med. 43 (12): 1351-8. doi:10.1515/CCLM.2005.231. PMID 16309372 ...
... is regulated by both allosteric control and by phosphorylation.. Hormones such as epinephrine, insulin and glucagon regulate glycogen phosphorylase using second messenger amplification systems that are linked to G proteins. Glucagon activates adenylate cyclase through a seven transmembrane receptor coupled to Gs which, in turn, activates adenylate cyclase to increase intracellular concentrations of cAMP. cAMP binds to and releases an active form of protein kinase A (PKA). Next, PKA phosphorylates phosphorylase kinase, which, in turn, phosphorylates glycogen phosphorylase b, transforming it into the active glycogen phosphorylase a. This phosphorylation is added onto the glycogen phosphorylase b serine 14. In the liver, glucagon activates another G-protein-linked receptor that triggers a different cascade, resulting in the activation of Phospholipase C (PLC). PLC indirectly causes the release of calcium from the ...
... (abbreviation: GPBB) is an isoenzyme of glycogen phosphorylase. This isoform of the enzyme exists in cardiac (heart) and brain tissue. The enzyme is one of the "new cardiac markers" which are discussed to improve early diagnosis in acute coronary syndrome. A rapid rise in blood levels can be seen in myocardial infarction and unstable angina. Other enzymes related to glycogen phosphorylase are abbreviated as GPLL (liver) and GPMM (muscle). Apple FS, Wu AH, Mair J, et al. (May 2005). "Future biomarkers for detection of ischemia and risk stratification in acute coronary syndrome". Clin. Chem. 51 (5): 810-24. doi:10.1373/clinchem.2004.046292. PMID 15774573. Peetz D, Post F, Schinzel H, et al. (2005). "Glycogen phosphorylase BB in acute coronary syndromes". Clin. Chem. Lab. Med. 43 (12): 1351-8. doi:10.1515/CCLM.2005.231. PMID 16309372 ...
... (UDP-glucose-glycogen glucosyltransferase) is a key enzyme in glycogenesis, the conversion of glucose into glycogen. It is a glycosyltransferase (EC 2.4.1.11) that catalyses the reaction of UDP-glucose and (1,4-α-D-glucosyl)n to yield UDP and (1,4-α-D-glucosyl)n+1. In other words, this enzyme combines excess glucose residues one by one into a polymeric chain for storage as glycogen. Glycogen synthase concentration is highest in the bloodstream 30 to 60 minutes following intense exercise. Much research has been done on glycogen degradation through studying the structure and function of glycogen phosphorylase, the key regulatory enzyme of glycogen degradation. On the other hand, much less is known about the structure of glycogen synthase, the key regulatory enzyme of glycogen synthesis. The crystal structure of glycogen synthase from Agrobacterium tumefaciens, however, has been determined at 2.3 A resolution. In its asymmetric form, glycogen synthase is found as a dimer, whose ...
In enzymology, a thymidine phosphorylase (EC 2.4.2.4) is an enzyme that catalyzes the chemical reaction thymidine + phosphate ⇌ {\displaystyle \rightleftharpoons } thymine + 2-deoxy-alpha-D-ribose 1-phosphate Thus, the two substrates of this enzyme are thymidine and phosphate, whereas its two products are thymine and 2-deoxy-alpha-D-ribose 1-phosphate. This enzyme is involved in metabolic pathways: purine metabolism/pyrimidine metabolism, bladder cancer, and in the diagnosis of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). This enzyme belongs to the family of glycosyltransferases, specifically the pentosyltransferases. The systematic name of this enzyme class is thymidine:phosphate deoxy-alpha-D-ribosyltransferase. Other names in common use include pyrimidine phosphorylase, thymidine-orthophosphate deoxyribosyltransferase, animal growth regulators, blood platelet-derived endothelial cell, growth factors, blood platelet-derived endothelial cell growth factor, ...
... (PNPase) is a bifunctional enzyme with a phosphorolytic 3' to 5' exoribonuclease activity and a 3'-terminal oligonucleotide polymerase activity.[2] That is, it dismantles the RNA chain starting at the 3' end and working toward the 5' end.[1] It also synthesizes long, highly heteropolymeric tails in vivo. It accounts for all of the observed residual polyadenylation in strains of Escherichia coli missing the normal polyadenylation enzyme.[1] Discovered by Marianne Grunberg-Manago working in Severo Ochoa's lab in 1955, the RNA-polymerization activity of PNPase was initially believed to be responsible for DNA-dependent synthesis of messenger RNA, a notion that got disproved by the late 1950s.[3][4] It is involved in mRNA processing and degradation in bacteria, plants,[5] and in humans.[6] In humans, the enzyme is encoded by the PNPT1 gene. In its active form, the protein forms a ring structure consisting of three PNPase molecules. Each PNPase molecule consists of two ...
Ochoa, S. and Mii, S. (1961). "Enzymatic synthesis of polynucleotides. IV. Purification and properties of polynucleotide phosphorylase from Azotobacter vinelandii". J. Biol. Chem. 236: 3303-3311. PMID 14481058. ...
... is regulated by both allosteric control and by phosphorylation.. Hormones such as epinephrine, insulin and glucagon regulate glycogen phosphorylase using second messenger amplification systems that are linked to G proteins. Glucagon activates adenylate cyclase through a seven transmembrane receptor coupled to Gs which, in turn, activates adenylate cyclase to increase intracellular concentrations of cAMP. cAMP binds to and releases an active form of protein kinase A (PKA). Next, PKA phosphorylates phosphorylase kinase, which, in turn, phosphorylates glycogen phosphorylase b, transforming it into the active glycogen phosphorylase a. This phosphorylation is added onto the glycogen phosphorylase b serine 14. In the liver, glucagon activates another G-protein-linked receptor that triggers a different cascade, resulting in the activation of Phospholipase C (PLC). PLC indirectly causes the release of calcium from the ...
... is regulated by both allosteric control and by phosphorylation.. Hormones such as epinephrine, insulin and glucagon regulate glycogen phosphorylase using second messenger amplification systems that are linked to G proteins. Glucagon activates adenylate cyclase through a seven transmembrane receptor coupled to Gs which, in turn, activates adenylate cyclase to increase intracellular concentrations of cAMP. cAMP binds to and releases an active form of protein kinase A (PKA). Next, PKA phosphorylates phosphorylase kinase, which, in turn, phosphorylates glycogen phosphorylase b, transforming it into the active glycogen phosphorylase a. This phosphorylation is added onto the glycogen phosphorylase b serine 14. In the liver, glucagon activates another G-protein-linked receptor that triggers a different cascade, resulting in the activation of Phospholipase C (PLC). PLC indirectly causes the release of calcium from the ...
Matsas, R., Fulcher, I.S., Kenny, A.J. and Turner, A.J. (1983). „Substance P and [Leu]enkephalin are hydrolyzed by an enzyme in pig caudate synaptic membranes that is identical with the endopeptidase of kidney microvilli". Proc. Natl Acad. Sci. USA. 80: 3111-3115. PMID 6190172 ...
Dizaltı arteriya (lat. Arteria poplitea) - bud arteriyasının ardı olub, dizaltı çuxurda yerləşmişdir. Yaxınlaşdırıcı kanalın aşağı dəliyi səviyyəsində başlayaraq dizaltı əzələnin və diz oynağının kapsulunun arxa səthi ilə aşağıya doğru gedir və dizaltı əzələnin aşağı kənarına çatır. Dizaltı arteriya dizaltı çuxurda vena və sinirlərə nisbətən ən dərində yerləşmişdir. Dizaltı vena - lat. V. poplitea dizaltı arteriyanın bayır və arxa tərəfində, qamış siniri - lat. N. tibialis isə bir az səthdə və bayır tərəfdə yerləşmişdir. Belə ki, səthdən getsək, əvvəlcə bayır tərəfdə və səthdə qamış sinirinə, bir az içəri tərəfdə və dərində dizaltı venaya və ondan da bir az dərində və içəri tərəfdə dizaltı arteriyaya rast gəlinir. ...
In mammals, methylation occurs in the liver by methyltransferases, the products being the (CH3)2AsOH (dimethylarsinous acid) and (CH3)2As(O)OH (dimethylarsinic acid), which have the oxidation states As(III) and As(V), respectively.[2] Although the mechanism of methylation of arsenic in humans has not been elucidated, the source of methyl is methionine, which suggests a role of S-adenosyl methionine.[25] Exposure to toxic doses begin when the liver's methylation capacity is exceeded or inhibited. There are two major forms of arsenic that can enter the body, arsenic (III) and arsenic (V).[26] Arsenic (III) enters the cells though aquaporins 7 and 9, which is a type of aquaglyceroporin.[26] Arsenic (V) compounds use phosphate transporters to enter cells.[26] The arsenic (V) can be converted to arsenic (III) by the enzyme purine nucleoside phosphorylase.[26] This is classified as a bioactivation step, as although arsenic (III) is more toxic, it is more readily methylated.[27]. There are two ...