Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dimethyl sulfoxide produces an opposite effect on the esterase and amidase activities of bovine thrombin. The esterase activity is increased by two fold but the amidase activity is decreased to 9% of the initial activity in 20% dimethyl sulfoxide. The stimulation of the esterase activity is due to the change in Vmax rather than Km for the substrate p-Tosyl-L-Arginine methyl ester. The inhibition of the esterase activity of thrombin by NaCl is not affected due to the addition of dimethyl sulfoxide. Ki for NaCl, 0.03 M, is the same for both in the absence and in the presence of 10% dimethyl sulfoxide. The catalytic activity of thrombin is inhibited by heparin. This effect is significantly decreased by dimethyl sulfoxide. The dissociation constant of heparin-thrombin complex, measured in the absence and in the presence of 10% dimethyl sulfoxide are 4 nM and 28 nM respectively. Thermal stability of thrombin, determined by monitoring catalytic activity, is increased in the presence of dimethyl sulfoxide. The enhancement of the fluorescence intensity of thrombin in the presence of dimethyl sulfoxide reflects the contribution of more exposed tryptophanyl residues. The alteration of the conformation of the enzyme structure due to the perturbation of the aqueous medium by dimethyl sulfoxide, has been attributed to these observed effects.
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PMID:The catalytic activity and physical properties of bovine thrombin in the presence of dimethyl sulfoxide. 684 75

Snake venom from Agkistrodon acutus consists of a number of compounds which may potentially be used as drugs. However, it is hard to obtain enough pure protein for drug development. Recently, we reported expression and purification of a novel recombinant fibrinogenase which was named rFII. Here we reported for the first time the enzymatic activities and functional characterization of rFII. Circular dichroism spectra showed the gross conformation of FIIa and rFII to be notably similar. It is an alkaline proteinase and the amino acid sequence exhibits a high degree of sequence identity with other snake venom metalloproteinases. rFII also exhibits amidase activity against N-(p-Tosyl)-Gly-Pro-Lys-p-nitroanilide, which is specified synthetic substrate for plasmin. Functional characterization showed that rFII possesses both fibronectin and type IV collagen cleaving activities. In addition, rFII preferentially cleaved the Aalpha-chain of fibrinogen, followed by the Bbeta-chain and finally, the gamma(gamma) chain was affected. Furthermore, rFII was also capable of cleaving fibrin without plasminogen activation and suppressing ADP-induced platelet aggregation. The proteolytic activity of rFII was inhibited completely by PMSF and mostly by EDTA. The cations Ca(2+), Mg(2+), Na(+), K(+) didn't affect its proteolytic activity, while Cu(2+) and Zn(2+) slightly inhibited this activity. Study of hydrolysis of oxidized insulin B-chain reveals that rFII preferentially cleaved oxidized insulin B-chain at the site of Val(12)-Glu(13), Leu(15)-Tyr(16), and Phe(24)-Phe(25).
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PMID:Enzymatic activities and functional characterization of a novel recombinant snake venom proteinase from Agkistrodon acutus. 1901 10