Hydrolysis of substituted trifluoroacetanilides. Implications for the mechanism of action of serine proteases

1972 ◽  
Vol 94 (22) ◽  
pp. 7887-7891 ◽  
Author(s):  
C. E. Stauffer
Keyword(s):  
Mechanism Of Action ◽  
Serine Proteases ◽  
Hydrolysis Of

scholarly journals Pharmacological Characterisation of Pseudocerastes and Eristicophis Viper Venoms Reveal Anticancer (Melanoma) Properties and a Potentially Novel Mode of Fibrinogenolysis

2021 ◽  
Vol 22 (13) ◽  
pp. 6896
Author(s):  
Bianca op den Brouw ◽  
Parviz Ghezellou ◽  
Nicholas R. Casewell ◽  
Syed Abid Ali ◽  
Behzad Fathinia ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Serine Proteases ◽  
Human Melanoma ◽  
Snake Venoms ◽  
Lead Compounds ◽  
Bioactive Properties ◽  
Fibrinogenolytic Activity ◽  
Pharmacological Potential ◽  
Hydrolysis Of ◽  
Viper Venoms

Venoms are a rich source of potential lead compounds for drug discovery, and descriptive studies of venom form the first phase of the biodiscovery process. In this study, we investigated the pharmacological potential of crude Pseudocerastes and Eristicophis snake venoms in haematological disorders and cancer treatment. We assessed their antithrombotic potential using fibrinogen thromboelastography, fibrinogen gels with and without protease inhibitors, and colourimetric fibrinolysis assays. These assays indicated that the anticoagulant properties of the venoms are likely induced by the hydrolysis of phospholipids and by selective fibrinogenolysis. Furthermore, while most fibrinogenolysis occurred by the direct activity of snake venom metalloproteases and serine proteases, modest evidence indicated that fibrinogenolytic activity may also be mediated by selective venom phospholipases and an inhibitory venom-derived serine protease. We also found that the Pseudocerastes venoms significantly reduced the viability of human melanoma (MM96L) cells by more than 80%, while it had almost no effect on the healthy neonatal foreskin fibroblasts (NFF) as determined by viability assays. The bioactive properties of these venoms suggest that they contain a number of toxins suitable for downstream pharmacological development as candidates for antithrombotic or anticancer agents.

Insights into chaperonin function from studies on archaeal thermosomes

2011 ◽  
Vol 39 (1) ◽  
pp. 94-98 ◽  
Author(s):  
Peter Lund
Keyword(s):  
Cell Death ◽  
Protein Folding ◽  
Recent Work ◽  
Mechanism Of Action ◽  
Molecular Chaperones ◽  
Short Review ◽  
Living Cells ◽  
Living Organisms ◽  
Opening And Closing ◽  
Hydrolysis Of

It is now well understood that, although proteins fold spontaneously (in a thermodynamic sense), many nevertheless require the assistance of helpers called molecular chaperones to reach their correct and active folded state in living cells. This is because the pathways of protein folding are full of traps for the unwary: the forces that drive proteins into their folded states can also drive them into insoluble aggregates, and, particularly when cells are stressed, this can lead, without prevention or correction, to cell death. The chaperonins are a family of molecular chaperones, practically ubiquitous in all living organisms, which possess a remarkable structure and mechanism of action. They act as nanoboxes in which proteins can fold, isolated from their environment and from other partners with which they might, with potentially deleterious consequences, interact. The opening and closing of these boxes is timed by the binding and hydrolysis of ATP. The chaperonins which are found in bacteria are extremely well characterized, and, although those found in archaea (also known as thermosomes) and eukaryotes have received less attention, our understanding of these proteins is constantly improving. This short review will summarize what we know about chaperonin function in the cell from studies on the archaeal chaperonins, and show how recent work is improving our understanding of this essential class of molecular chaperones.

Jack bean urease (EC 3.5.1.5). V. On the mechanism of action of urease on urea, formamide, acetamide, N-methylurea, and related compounds

1980 ◽  
Vol 58 (12) ◽  
pp. 1335-1344 ◽  
Author(s):  
Nicholas E. Dixon ◽  
Peter W. Riddles ◽  
Carlo Gazzola ◽  
Robert L. Blakeley ◽  
Burt Zerner
Keyword(s):  
Enzymatic Hydrolysis ◽  
Mechanism Of Action ◽  
Active Site ◽  
Ph Dependence ◽  
Jack Bean Urease ◽  
Nickel Ion ◽  
Jack Bean ◽  
First Time ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

Acetamide and N-methylurea have been shown for the first time to be substrates for jack bean urease. In the enzymatic hydrolysis of urea, formamide, acetamide, and N-methylurea at pH 7.0 and 38 °C, kcat has the values 5870, 85, 0.55, and 0.075 s−1, respectively. The urease-catalyzed hydrolysis of all these substrates involves the active-site nickel ion(s). Enzymatic hydrolysis of the following compounds could not be detected: phenyl formate, p-nitroformanilide, trifluoroacetamide, p-nitrophenyl carbamate, thiourea, and O-methylisouronium ion. In the enzymatic hydrolysis of urea, the pH dependence of kcat between pH 3.4 and 7.8 indicates that at least two prototropic forms are active. Enzymatic hydrolysis of urea in the presence of methanol gave no detectable methyl carbamate. A mechanism of action for urease is proposed which involves initially an O-bonded complex between urea and an active-site Ni2+ ion and subsequently an O-bonded carbamato–enzyme intermediate.

An Isozyme of Earthworm Serine Proteases Acts on Hydrolysis of Triacylglycerol

2005 ◽  
Vol 69 (10) ◽  
pp. 2009-2011 ◽  
Author(s):  
Nobuyoshi NAKAJIMA ◽  
Manabu SUGIMOTO ◽  
Sadao TSUBOI ◽  
Hideaki TSUJI ◽  
Kohji ISHIHARA
Keyword(s):  
Serine Proteases ◽  
Hydrolysis Of
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