scholarly journals The death enzyme CP14 is a unique papain-like cysteine proteinase with a pronounced S2 subsite selectivity

2016 ◽  
Vol 603 ◽  
pp. 110-117 ◽  
Author(s):  
Melanie Paireder ◽  
Ulrich Mehofer ◽  
Stefan Tholen ◽  
Andreas Porodko ◽  
Philipp Schähs ◽  
...  
Keyword(s):  
Cysteine Proteinase ◽  
S2 Subsite

scholarly journals Identification of signalling and non-signalling binding contributions to enzyme reactivity. Alternative combinations of binding interactions provide for change in transition-state geometry in reactions of papain

1989 ◽  
Vol 258 (3) ◽  
pp. 755-764 ◽  
Author(s):  
D Kowlessur ◽  
C M Topham ◽  
E W Thomas ◽  
M O'Driscoll ◽  
W Templeton ◽  
...  
Keyword(s):  
Transition State ◽  
Cysteine Proteinase ◽  
Ph Dependence ◽  
Thiol Group ◽  
Catalytic Site ◽  
Amide Bond ◽  
Compound I ◽  
Binding Interactions ◽  
Transition State Geometry ◽  
S2 Subsite

1. 2-(N'-Acetyl-L-phenylalanyl)hydroxyethyl 2′-pyridyl disulphide (compound V) was synthesized, and a study of the pH-dependence of the second-order rate constant (k) for its reaction with the catalytic-site thiol group of papain (EC 3.4.22.2) was used to evaluate the consequences for transition-state geometry of the presence of a hydrophobic occupant for the S2 subsite of the enzyme in the absence of the N-H component of the P1-P2 amide bond. 2. Comparison of the pH-dependences of K for reactions of compound (V), 2-(acetamido)ethyl 2′-pyridyl disulphide (compound I) and 2-(acetoxy)ethyl 2′-pyridyl disulphide (compound III) with the cysteine-proteinase minimal catalytic-site model, benzimidazol-2-ylmethanethiol, established the activation of all of these pyridyl disulphides by hydronation and that their reactivities are relatively insensitive to structural change in the non-pyridyl part of the molecule. The marked differences in their reactivities towards papain therefore derive from binding, either directly, or indirectly via signalling mechanisms. 3. Comparison of the kinetic data for the reaction of papain with compound (V) with those for analogous reactions with reactivity probes that provide opportunities for a variety of binding interactions in the S1-S2 intersubsite region and in the S2 subsite itself lead to the following conclusions: (a) the (Gly-66) N-H...O = C less than (P1-P2 ester) interaction of papain with compound (III) provides for better binding relative to that for a probe with a simple hydrocarbon side chain, but no signalling to the catalytic site to provide a (His-159)-ImH+-assisted transition state; (b) when this interaction is augmented either by a (P1-P2 amide) N-H...O = C less than (Asp-158) interaction (compound I) or hydrophobic P2/S2 contacts (compound V), signalling to the catalytic region occurs to provide the assisted transition state; (c) when both the P2/S2 contacts and the interaction involving Gly-66 exist, provision additionally of the (P1-P2 amide) N-H...O = C less than (Asp-158) interaction [as in 2-(N'-acetyl-L-phenylalanylamino)ethyl 2′-pyridyl disulphide] serves only to assist the binding without an additional signalling effect. 4. Such studies promise to allow binding interactions that merely locate substrates in appropriate enzyme loci to be distinguished from those that transmit signals with a chemical consequence to catalytic sites.

scholarly journals Consequences of molecular recognition in the S1-S2 intersubsite region of papain for catalytic-site chemistry. Change in pH-dependence characteristics and generation of an inverse solvent kinetic isotope effect by introduction of a P1-P2 amide bond into a two-protonic-state reactivity probe

1988 ◽  
Vol 250 (3) ◽  
pp. 761-772 ◽  
Author(s):  
K Brocklehurst ◽  
D Kowlessur ◽  
G Patel ◽  
W Templeton ◽  
K Quigley ◽  
...  
Keyword(s):  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
Cysteine Proteinase ◽  
Catalytic Site ◽  
Amide Bond ◽  
Nucleophilic Attack ◽  
Kinetic Isotope ◽  
Rate Maximum ◽  
Imidazolium Ion ◽  
S2 Subsite

1. The pH-dependences of the second-order rate constant (k) for the reactions of papain (EC 3.4.22.2) with 2-(acetamido)ethyl 2′-pyridyl disulphide and with ethyl 2-pyridyl disulphide and of k for the reaction of benzimidazol-2-ylmethanethiol (as a minimal model of cysteine proteinase catalytic sites) with the former disulphide were determined in aqueous buffers at 25 degrees C at I 0.1. 2. Of these three pH-k profiles only that for the reaction of papain with 2-(acetamido)ethyl 2′-pyridyl disulphide has a rate maximum at pH approx. 6; the others each have a rate minimum in this pH region and a rate maximum at pH 4, which is characteristic of reactions of papain with other 2-pyridyl disulphides that do not contain a P1-P2 amide bond in the non-pyridyl part of the molecule. 3. The marked change in the form of the pH-k profile consequent upon introduction of a P1-P2 amide bond into the probe molecule for the reaction with papain but not for that with the minimal catalytic-site model is interpreted in terms of the induction by binding of the probe in the S1-S2 intersubsite region of the enzyme of a transition-state geometry in which nucleophilic attack by the -S- component of the catalytic site is assisted by association of the imidazolium ion component with the leaving group. 4. The greater definition of the rate maximum in the pH-k profile for the reaction of papain with an analogous 2-pyridyl disulphide reactivity probe containing both a P1-P2 amide bond and a potential occupant for the S2 subsite [2-(N'-acetyl-L-phenylalanylamino)ethyl 2′-pyridyl disulphide [Brocklehurst, Kowlessur, O'Driscoll, Patel, Quenby, Salih, Templeton, Thomas & Willenbrock (1987) Biochem. J. 244, 173-181]) suggests that a P2-S2 interaction substantially increases the population of transition states for the imidazolium ion-assisted reaction. 5. The overall kinetic solvent 2H-isotope effect at pL 6.0 was determined to be: for the reaction of papain with 2,2′-dipyridyl disulphide, 0.96 (i.e. no kinetic isotope effect), for its reaction with the probe containing only the P1-P2 amide bond, 0.75, for its reaction with the probe containing both the P1-P2 amide bond and the occupant for the S2 subsite, 0.61, and for kcat./Km for its catalysis of the hydrolysis of N-methoxycarbonylglycine 4-nitrophenyl ester, 0.67.(ABSTRACT TRUNCATED AT 400 WORDS)

Major Kinds of Drug Targets in Chagas Disease or American Trypanosomiasis

2019 ◽  
Vol 20 (11) ◽  
pp. 1203-1216 ◽  
Author(s):  
Vilma G. Duschak
Keyword(s):  
Chagas Disease ◽  
Latin American ◽  
Drug Targets ◽  
Defense Mechanisms ◽  
Cysteine Proteinase ◽  
Parasitic Infection ◽  
Etiologic Agent ◽  
World Health ◽  
American Trypanosomiasis ◽  
Group I

American Trypanosomiasis, a parasitic infection commonly named Chagas disease, affects millions of people all over Latin American countries. Presently, the World Health Organization (WHO) predicts that the number of international infected individuals extends to 7 to 8 million, assuming that more than 10,000 deaths occur annually. The transmission of the etiologic agent, Trypanosoma cruzi, through people migrating to non-endemic world nations makes it an emergent disease. The best promising targets for trypanocidal drugs may be classified into three main groups: Group I includes the main molecular targets that are considered among specific enzymes involved in the essential processes for parasite survival, principally Cruzipain, the major antigenic parasite cysteine proteinase. Group II involves biological pathways and their key specific enzymes, such as Sterol biosynthesis pathway, among others, specific antioxidant defense mechanisms, and bioenergetics ones. Group III includes the atypical organelles /structures present in the parasite relevant clinical forms, which are absent or considerably different from those present in mammals and biological processes related to them. These can be considered potential targets to develop drugs with extra effectiveness and fewer secondary effects than the currently used therapeutics. An improved distinction between the host and the parasite targets will help fight against this neglected disease.

Molecular Characterization and Mapping of Murine Genes Encoding Three Members of the Stefin Family of Cysteine Proteinase Inhibitors

Genomics ◽  
1993 ◽  
Vol 15 (3) ◽  
pp. 507-514 ◽  
Author(s):  
Florence W.L. Tsui ◽  
Hing-Wo Tsui ◽  
Samuel Mok ◽  
Irena Mlinaric ◽  
Neal G. Copeland ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Cysteine Proteinase Inhibitors ◽  
Genes Encoding

scholarly journals A novel cysteine proteinase inhibitor from seeds of Enterolobium contortisiliquum and its effect on Callosobruchus maculatus larvae

2021 ◽  
Vol 25 ◽  
pp. 100876
Author(s):  
Natalia N.S. Nunes ◽  
Rodrigo S. Ferreira ◽  
Leonardo F.R. de Sá ◽  
Antônia Elenir A. de Oliveira ◽  
Maria Luiza V. Oliva
Keyword(s):  
Proteinase Inhibitor ◽  
Callosobruchus Maculatus ◽  
Cysteine Proteinase ◽  
Cysteine Proteinase Inhibitor

scholarly journals Identification of pyrogallol as a warhead in design of covalent inhibitors for the SARS-CoV-2 3CL protease

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Haixia Su ◽  
Sheng Yao ◽  
Wenfeng Zhao ◽  
Yumin Zhang ◽  
Jia Liu ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Cysteine Proteinase ◽  
Covalent Binding ◽  
Food Sources ◽  
Binding Mechanism ◽  
Covalent Inhibitors ◽  
Catalytic Cysteine ◽  
3Cl Protease ◽  
Covalent Ligands ◽  
Covalent Inhibitor

AbstractThe ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) urgently needs an effective cure. 3CL protease (3CLpro) is a highly conserved cysteine proteinase that is indispensable for coronavirus replication, providing an attractive target for developing broad-spectrum antiviral drugs. Here we describe the discovery of myricetin, a flavonoid found in many food sources, as a non-peptidomimetic and covalent inhibitor of the SARS-CoV-2 3CLpro. Crystal structures of the protease bound with myricetin and its derivatives unexpectedly revealed that the pyrogallol group worked as an electrophile to covalently modify the catalytic cysteine. Kinetic and selectivity characterization together with theoretical calculations comprehensively illustrated the covalent binding mechanism of myricetin with the protease and demonstrated that the pyrogallol can serve as an electrophile warhead. Structure-based optimization of myricetin led to the discovery of derivatives with good antiviral activity and the potential of oral administration. These results provide detailed mechanistic insights into the covalent mode of action by pyrogallol-containing natural products and a template for design of non-peptidomimetic covalent inhibitors against 3CLpros, highlighting the potential of pyrogallol as an alternative warhead in design of targeted covalent ligands.

Specific cleavage sites on human IgG subclasses by cruzipain, the major cysteine proteinase from Trypanosoma cruzi

2003 ◽  
Vol 130 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Patricia Berasain ◽  
Carlos Carmona ◽  
Blas Frangione ◽  
Juan José Cazzulo ◽  
Fernando Goñi
Keyword(s):  
Trypanosoma Cruzi ◽  
Cysteine Proteinase ◽  
Igg Subclasses ◽  
Cleavage Sites ◽  
Human Igg

Purification and Structure of a Novel Cysteine Proteinase Inhibitor, Strepin P-1

1985 ◽  
Vol 49 (3) ◽  
pp. 799-805
Author(s):  
Kyoichi Ogura ◽  
Mitsuru Maeda ◽  
Masami Nagai ◽  
Takaharu Tanaka ◽  
Kyosuke Nomoto ◽  
...  
Keyword(s):  
Proteinase Inhibitor ◽  
Cysteine Proteinase ◽  
Cysteine Proteinase Inhibitor
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