Inhibition of bone resrption by selctive inactivators of cysteine proteinases

1994 ◽  
Vol 56 (1) ◽  
pp. 118-130 ◽  
Author(s):  
Peter A. Hill ◽  
David J. Buttle ◽  
Sheila J. Jones ◽  
Alan Boyde ◽  
Mitsuo Murata ◽  
...  
Keyword(s):  
Cysteine Proteinases

scholarly journals Inhibition of cysteine proteinases and dipeptidyl peptidase I by egg-white cystatin

1984 ◽  
Vol 223 (1) ◽  
pp. 245-253 ◽  
Author(s):  
M J H Nicklin ◽  
A J Barrett
Keyword(s):  
Cathepsin B ◽  
Bond Cleavage ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dipeptidyl Peptidase ◽  
Egg White ◽  
Reversible Inhibitor ◽  
Cysteine Proteinases ◽  
Peptide Bond Cleavage ◽  
Specific Oxidation

The interactions between egg-white cystatin and the cysteine proteinases papain, human cathepsin B and bovine dipeptidyl peptidase I were studied. Cystatin was shown to be a competitive reversible inhibitor of cathepsin B (Ki 1.7 nM, k-1 about 2.3×10(-3) s-1). The inhibition of dipeptidyl peptidase I was shown to be reversible (Ki(app.) 0.22 nM, k-1 about 2.2×10(-3) s-1). Cystatin bound papain too tightly for Ki to be determined, but an upper limit of 5 pM was estimated. The association was a second-order process, with k+1 1.0×10(7) M-1×s-1. Papain was shown to form equimolar complexes with cystatin. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of complexes formed between papain or cathepsin B and an excess of cystatin showed no peptide bond cleavage after incubation for 72 h. The reaction of the active-site thiol group of papain with 5,5′-dithiobis-(2-nitrobenzoic acid) at pH 8 and 2,2′-dithiobispyridine at pH 4 was blocked by complex-formation. Dipeptidyl peptidase I and papain were found to compete for binding to cystatin, contrary to a previous report. The two major isoelectric forms of cystatin were found to have similar specific inhibitory activities for papain, and similar affinities for papain, cathepsin B and dipeptidyl peptidase I. This, together with specific oxidation of the N-terminal serine residue with periodate, showed the N-terminal amino group of cystatin 1 to be unimportant for inhibition. General citraconylation of amino groups resulted in a large decrease in the affinity of cystatin for dipeptidyl peptidase I. It is concluded that the interaction of cystatin with cysteine proteinases has many characteristics similar to those of an inhibitor such as aprotinin with serine proteinases.

Quantification of the expression levels of lysosomal cysteine proteinases in purified human osteoclastic cells by competitive RT-PCR

2001 ◽  
Vol 68 (2) ◽  
pp. 109-116 ◽  
Author(s):  
O. Ishibashi ◽  
T. Inui ◽  
Y. Mori ◽  
T. Kurokawa ◽  
T. Kokubo ◽  
...  
Keyword(s):  
Cysteine Proteinases ◽  
Rt Pcr ◽  
Expression Levels

scholarly journals Use of inhibitors to identify essential cysteine proteinases of Trichomonas vaginalis

2006 ◽  
Vol 149 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Joseph W Irvine ◽  
Michael J North ◽  
Graham H Coombs
Keyword(s):  
Trichomonas Vaginalis ◽  
Cysteine Proteinases

The structure and mechanism of action of papain

1970 ◽  
Vol 257 (813) ◽  
pp. 237-248 ◽  
Keyword(s):  
Mechanism Of Action ◽  
Catalytic Mechanism ◽  
Proteolytic Enzymes ◽  
Cysteine Proteinase ◽  
Preceding Paper ◽  
Cysteine Residue ◽  
Enzymic Activity ◽  
Critical Survey ◽  
Cysteine Proteinases ◽  
Stem Bromelain

The cysteine proteinases form a group of enzymes which depend for their enzymic activity on the thiol group of a cysteine residue. Several which occur in plants have been investigated extensively and include papain, ficin and stem bromelain (Smith & Kimmel i960). Although the term papain, introduced last century to describe the proteolytic principle in papaya latex (Wurtz & Bouchut 1879) is still used to describe crude dried latex, the crystalline enzyme is readily obtained (Kimmel & Smith 1954). Ficin is known to consist of several closely related enzymes which have been resolved (Sgarbieri, Gupte, Kramer & Whitaker 1964), but for most structural and mechanistic studies the unresolved mixture of enzymes has been used. Stem bromelain also appears to be a mixture of at least two proteolytic enzymes which have not yet been resolved (Ota, Moore & Stein 1962; Murachi 1964). In spite of the recognized heterogeneity of ficin and stem bromelain, it does seem that both structurally and mechanistically they are similar to papain. Only one bacterial cysteine proteinase has received a detailed study, namely, streptococcal proteinase, and it appears to have little or no relation in its amino acid sequence with the plant enzymes (Liu, Stein, Moore & Elliott 1965). The functional groups involved in the catalytic mechanism are apparently the same as in the plant proteinases (Gerwin, Stein & Moore 1966; Liu 1967; Husain & Lowe 1968 a , c ), but the mechanism of action has not been extensively studied. It may well be however that the plant and bacterial cysteine proteinases have converged onto a similar mechanism of action by two independent evolutionary pathways, as now seems apparent for the animal and bacterial serine proteinases (Alden, Wright & Kraut, this volume, p. 119). Because the tertiary crystal structure of papain (Drenth, Jansonius, Koekoek, Swen & Wolthers 1968; see also the preceding paper, p. 231) is now known, a critical survey of this enzyme is apposite.

Regulation of a novel pathway for cell death by lysosomal aspartic and cysteine proteinases

Neuroscience ◽  
1999 ◽  
Vol 91 (1) ◽  
pp. 233-249 ◽  
Author(s):  
K Isahara ◽  
Y Ohsawa ◽  
S Kanamori ◽  
M Shibata ◽  
S Waguri ◽  
...  
Keyword(s):  
Cell Death ◽  
Cysteine Proteinases

scholarly journals Evidence that the active centre of chymopapain A is different from the active centres of some other cysteine proteinases and that the Brønsted coefficient (βnuc.) for the reactions of thiolate anions with 2,2′-dipyridyl disulphide may be decreased by reagent protonation

1980 ◽  
Vol 189 (1) ◽  
pp. 189-192 ◽  
Author(s):  
K Brocklehurst ◽  
B S Baines ◽  
M S Mushiri
Keyword(s):  
Carica Papaya ◽  
Cysteine Proteinases ◽  
Active Centre ◽  
Pka Values ◽  
Nitrobenzoic Acid ◽  
Specific Reactivity ◽  
Ph Range ◽  
Thiolate Anions ◽  
Active Centres

The active centres of chymopapains A and B (jointly designated EC 3.4.22.6) and papaya (Carica papaya L.) peptidase A were investigated by using 2,2′-dipyridyl disulphide and 5,5′-dithiobis-(2-nitrobenzoic acid) as thiol-specific reactivity probes. Whereas the first active-centre pKa values for chymopapain B and papaya peptidase A are less than 5, is as the case for papain (EC 3.4.22.2) and ficin (EC 3.4.22.3), that for chymopapain A is about 6.8. The reason why the reactions of thiols of pKa approx. 6.5 with 2.2′-dipyridyl disulphide are essentially pH-independent in the pH range around the thiol pKa is delineated. The value of the Brønsted coefficient (beta nuc.) for the reactions of thiolate ions with the 2,2′-dipyridyl disulphide monocation appears to be smaller than its value for the corresponding reactions with the neutral disulphide.

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