Substrate specificity of recombinant dengue 2 virus NS2B-NS3 protease: Influence of natural and unnatural basic amino acids on hydrolysis of synthetic fluorescent substrates

2007 ◽  
Vol 457 (2) ◽  
pp. 187-196 ◽  
Author(s):  
I.E. Gouvea ◽  
M.A. Izidoro ◽  
W.A.S. Judice ◽  
M.H.S. Cezari ◽  
G. Caliendo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Substrate Specificity ◽  
Basic Amino Acids ◽  
Ns3 Protease ◽  
Hydrolysis Of

Isolation and partial characterization of a peptidase with trypsin-like activity from bovine adenohypophysis

1989 ◽  
Vol 54 (8) ◽  
pp. 2276-2286
Author(s):  
Tsezengijn Dash ◽  
Tomislav Barth ◽  
Jiřina Slaninová ◽  
Jana Barthová ◽  
Hana P. Mašková ◽  
...  
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Partial Characterization ◽  
Chromogenic Substrate ◽  
Fluorogenic Substrate ◽  
Basic Amino Acids ◽  
Optimum Ph ◽  
Reproducible Method ◽  
Hydrolysis Of

A reproducible method has been developed for the isolation of the adenohypophyseal enzyme with a trypsin-like activity. The enzyme is able to hydrolyze Nα-benzoyl-L-arginine-p-nitroanilide, a fluorogenic substrate CBzl-Arg-Arg-β-naphthyl amide and some peptides with one or two accumulated basic amino acids in the chain. The optimum pH for hydrolysis of the chromogenic substrate was within the range 6.0-7.0 (Km = 0.66 mmol l-1), in the case of the fluorogenic substrate the range was between 7.0 and 7.5 (Km = 1.2 μmol l-1). The enzyme is activated by cysteine and dithiothreitol and inhibited by SH-poisons. The molecular weight of the enzyme, determined by means of two independent methods, was approximately 25 kDA.

scholarly journals Roles of Amino Acids 161 to 179 in the PSE-4 Ω Loop in Substrate Specificity and in Resistance to Ceftazidime

1998 ◽  
Vol 42 (10) ◽  
pp. 2576-2583 ◽  
Author(s):  
Christian Therrien ◽  
Francois Sanschagrin ◽  
Timothy Palzkill ◽  
Roger C. Levesque
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Specificity ◽  
High Activity ◽  
Amino Acid Substitutions ◽  
Hydrolyzing Enzymes ◽  
Hydrolysis Of

ABSTRACT The PSE-4 enzyme is a prototype carbenicillin-hydrolyzing enzyme exhibiting high activity against penicillins and early cephalosporins. To understand the mechanism that modulates substrate profiles and to verify the ability of PSE-4 to extend its substrate specificity toward expanded-spectrum cephalosporins, we used random replacement mutagenesis to generate six random libraries from amino acids 162 to 179 in the Ω loop. This region is known from studies with TEM-1 to be implicated in substrate specificity. It was found that the mechanism modulating ceftazidime hydrolysis in PSE-4 was different from that in TEM-1. The specificity of class 2c carbenicillin-hydrolyzing enzymes could not be assigned to the Ω loop of PSE-4. Analysis of the percentage of functional enzymes revealed that the hydrolysis of ampicillin was more affected than hydrolysis of carbenicillin by amino acid substitutions at positions 162 to 164 and 165 to 167.

scholarly journals Direct Monitoring of Biocatalytic Deacetylation Reactions by 1H NMR Reveals Fine Details of Substrate Specificity.

2021 ◽  
Author(s):  
Silvia De Cesare ◽  
Catherine A McKenna ◽  
Lorna Murray ◽  
Juraj Bella ◽  
Nicholas P Mulholland ◽  
...  
Keyword(s):  
Amino Acids ◽  
Substrate Specificity ◽  
1H Nmr ◽  
Building Blocks ◽  
Hydrolysis Of

Amino acids are key synthetic building blocks that can be prepared in an entiopure form by biocatalytic methods. We show that the L-selective ornithine deacetylase ArgE catalyses hydrolysis of a...

scholarly journals The dynamics of free amino acids in the grains Tripogon chinensis (Franch.) Hack. when germinating in the conditions of the osmotic stress

2018 ◽  
Vol 11 ◽  
pp. 00033
Author(s):  
Irina Plyaskina ◽  
Evgenii Bondarevich ◽  
Igor Boriskin ◽  
Natalia Kotsyurzhinskaya ◽  
Ludmila Ishina
Keyword(s):  
Amino Acids ◽  
Osmotic Stress ◽  
Osmotic Pressure ◽  
Free Amino Acids ◽  
Free Amino ◽  
Basic Amino Acids ◽  
Protective Signaling ◽  
Hydrolysis Of ◽  
Arginine Concentration ◽  
Adaptive Reaction

The content of free amino acids in seeds and sprouts of T. chinensis in the control and at an osmotic pressure of 5 atm. was determined. The group of acidic and basic amino acids predominates in seeds. An adaptive reaction to a physiological drought is the transformation of the free amino acids metabolism. This is expressed in an increase in the total amount of free amino acids at the osmotic pressure of 5 atm., providing the osmotic component of adaptation. Under the conditions of the osmotic stress, the concentration of acidic and basic amino acids increases up to 48 hours, this may be due to the continued hydrolysis of reserve proteins. Under the influence of the osmotic stress there are changes in the group of amino acids, the metabolic precursor of which is glutamic acid. The amino acids, a part of this group, exhibit protective, signaling properties. Thus, the increase in the arginine concentration and ornithine is noted; this indicates the activation of the ornithine cycle and on the increase of amino acids catabolism. The revealed features can ensure the successful germination of T. chinensis grains under the conditions of the physiological drought.

scholarly journals Roles of Residues Cys69, Asn104, Phe160, Gly232, Ser237, and Asp240 in Extended-Spectrum β-Lactamase Toho-1

2010 ◽  
Vol 55 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Akiko Shimizu-Ibuka ◽  
Mika Oishi ◽  
Shoko Yamada ◽  
Yoshikazu Ishii ◽  
Kiyoshi Mura ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Binding Site ◽  
Kinetic Properties ◽  
Amino Acid Residues ◽  
Class A ◽  
Extended Spectrum ◽  
Hydrolysis Of

ABSTRACTToho-1, which is also designated CTX-M-44, is an extended-spectrum class A β-lactamase that has high activity toward cefotaxime. In this study, we investigated the roles of residues suggested to be critical for the substrate specificity expansion of Toho-1 in previous structural analyses. Six amino acid residues were replaced one by one with amino acids that are often observed in the corresponding position of non-extended-spectrum β-lactamases. The mutants produced inEscherichia colistrains were analyzed both for their kinetic properties and their effect on drug susceptibilities. The results indicate that the substitutions of Asn104 and Ser237 have certain effects on expansion of substrate specificity, while those of Cys69 and Phe160 have less effect, and that of Asp240 has no effect on the hydrolysis of any substrates tested. Gly232, which had been assumed to increase the flexibility of the substrate binding site, was revealed not to be critical for the expansion of substrate specificity of this enzyme, although this substitution resulted in deleterious effects on expression and stability of the enzyme.

Design of Inhibitors for Human Tissue Kallikrein Using Non-Natural Aromatic and Basic Amino Acids

2002 ◽  
Vol 383 (5) ◽  
pp. 853-857 ◽  
Author(s):  
Daniel C. Pimenta ◽  
Robson L. Melo ◽  
Giuseppe Caliendo ◽  
Vincenzo Santagada ◽  
Ferdinando Fiorino ◽  
...  
Keyword(s):  
Amino Acids ◽  
Substrate Specificity ◽  
Human Tissue ◽  
Side Chains ◽  
Tissue Kallikrein ◽  
Urinary Kallikrein ◽  
Nonnatural Amino Acids ◽  
Basic Amino Acids ◽  
Competitive Inhibitors ◽  
Hydrophobic Amino Acids

Abstract We explored the unique substrate specificity of the primary S1 subsite of human urinary kallikrein (hK1), which accepts both Phe or Arg synthesizing and assaying peptides derived from PhenylacetylPheSer ArgEDDnp, a previously described inhibitor with analgesic and antiinflammatory activities [Emim et al., Br. J. Pharmacol. 130 (2000), 1099 1107]. Phe was substituted by amino acids containing larger aliphatic or aromatic side chains as well as by nonnatural basic amino acids, which were designed to combine a large hydrophobic and/or aromatic group with a positivelycharged group at their side chains. In general, all peptides with basic amino acids represented better inhibitors than those with hydrophobic amino acids. Furthermore, the S1 subsite specificity proved to be much more selective than the mere distinction between Phe and Arg, for minor differences in the side chains of the nonnatural amino acids resulted in major differences in the Ki values. Finally, we present a series of peptides that were assayed as competitive inhibitors for human tissue kallikrein that may lead to the development of novel peptides, which are both more potent and selective.

Does the polyamine carrier system absorb basic amino acids?

2001 ◽  
Vol 120 (5) ◽  
pp. A142-A142
Author(s):  
J GASKEY ◽  
E SEIDEL
Keyword(s):  
Amino Acids ◽  
Carrier System ◽  
Basic Amino Acids

Deinking of recycled paper by coupling of the enzyme endo-β-1,4-D-glucanasa and the cellulose, and by using a laboratory flotation column

MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2669-2678
Author(s):  
Jeovani González P. ◽  
Ramiro Escudero G
Keyword(s):  
Amino Acids ◽  
Sodium Hydroxide ◽  
Paper Industry ◽  
Computational Simulation ◽  
Cellulose Fibers ◽  
Residual Water ◽  
Chemical Reagent ◽  
Recycled Paper ◽  
Flotation Column ◽  
Hydrolysis Of

AbstractDeinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.

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