Evidence that binding to the s2-subsite of papain may be coupled with catalytically relevant structural change involving the cysteine-25-histidine-159 diad. Kinetics of the reaction of papain with a two-protonic-state reactivity probe containing a hydrophobic side chain.

Current problems in mechanistic studies of serine and cysteine proteinases. Biochem J (1982) 1.71

Differences in the interaction of the catalytic groups of the active centres of actinidin and papain. Rapid purification of fully active actinidin by covalent chromatography and characterization of its active centre by use of two-protonic-state reactivity probes. Biochem J (1981) 1.60

Evidence that the active centre of chymopapain A is different from the active centres of some other cysteine proteinases and that the Brønsted coefficient (beta nuc.) for the reactions of thiolate anions with 2,2'-dipyridyl disulphide may be decreased by reagent protonation. Biochem J (1980) 1.44

Evidence for a two-state transition in papain that may have no close analogue in ficin. Differences in the disposition of cationic sites and hydrophobic binding areas in the active centres of papain and ficin. Biochem J (1980) 1.39

Characterization of papaya peptidase A as a cysteine proteinase of Carica papaya L. with active-centre properties that differ from those of papain by using 2,2'-dipyridyl disulphide and 4-chloro-7-nitrobenzofurazan as reactivity probes. Use of two-protonic-state electrophiles in the identification of catalytic-site thiol groups. Biochem J (1982) 1.24

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. Biochem J (1988) 1.22

Reactivities of neutral and cationic forms of 2,2'-dipyridyl disulphide towards thiolate anions. Detection of differences between the active centres of actinidin, papain and ficin by a three-protonic-state reactivity probe. Biochem J (1979) 1.19

Effects of conformational selectivity and of overlapping kinetically influential ionizations on the characteristics of pH-dependent enzyme kinetics. Implications of free-enzyme pKa variability in reactions of papain for its catalytic mechanism. Biochem J (1983) 1.19

Evidence that the lack of high catalytic activity of thiolsubtilisin towards specific substrates may be due to an inappropriately located proton-distribution system. Demonstration of highly nucleophilic character of the thiol group of thiolsubtilisin in the catalytically relevant ionization state of the active centre by use of a two-protonic-state reactivity probe. Biochem J (1981) 0.94

Evidence for association-activation effects in reactions of papain from studies on its reactivity towards isomeric two-protonic-state reactivity probes. Biochem J (1979) 0.89

Kinetic solvent isotope effects on the deacylation of specific acyl-papains. Proton inventory studies on the papain-catalysed hydrolyses of specific ester substrates: analysis of possible transition state structures. Biochem J (1981) 0.84

Entropic contributions to rate accelerations in enzymic and intramolecular reactions and the chelate effect. Proc Natl Acad Sci U S A (1971) 5.46

A source for the special catalytic power of enzymes: orbital steering. Proc Natl Acad Sci U S A (1970) 4.45

The catalytic and regulatory properties of enzymes. Annu Rev Biochem (1968) 4.34

Reactions of papain and of low-molecular-weight thiols with some aromatic disulphides. 2,2'-Dipyridyl disulphide as a convenient active-site titrant for papain even in the presence of other thiols. Biochem J (1973) 3.33

Mapping the active site of papain with the aid of peptide substrates and inhibitors. Philos Trans R Soc Lond B Biol Sci (1970) 3.29

A reporter group delivery system with both absolute and selective specificity for thiol groups and an improved fluorescent probe containing the 7-nitrobenzo-2-oxa-1,3-diazole moiety. Biochem J (1975) 3.17

Structure of papain. Nature (1968) 3.02

Covalent chromatography. Preparation of fully active papain from dried papaya latex. Biochem J (1973) 2.79

Preparation of fully active ficin from Ficus glabrata by covalent chromatography and characterization of its active centre by using 2,2'-depyridyl disulphide as a reactivity probe. Biochem J (1976) 2.53

Characterization of the papain active centre by using two-protonic-state electrophiles as reactivity probes. Evidence for nucleophilic reactivity in the un-interrupted cysteine-25-histidine-159 interactive system. Biochem J (1978) 2.21

A necessary modification to the preparation of papain from any high-quality latex of Carica papaya and evidence for the structural integrity of the enzyme produced by traditional methods. Biochem J (1979) 2.20

Specific covalent modification of thiols: applications in the study of enzymes and other biomolecules. Int J Biochem (1979) 2.11

The equilibrium assumption is valid for the kinetic treatment of most time-dependent protein-modification reactions. Biochem J (1979) 1.82

The pH-dependence of second-order rate constants of enzyme modification may provide free-reactant pKa values. Biochem J (1977) 1.73

Covalent chromatography by thiol-disulfide interchange. Methods Enzymol (1974) 1.61

A spectrophotometric method for the detection of contaminant chymopapains in preparations of papain. Selective modification of one type of thiol group in the chymopapains by a two-protonic-state reagent. Biochem J (1978) 1.52

Mechanism of the reaction of papain with substrate-derived diazomethyl ketones. Implications for the difference in site specificity of halomethyl ketones for serine proteinases and cysteine proteinases and for stereoelectronic requirements in the papain catalytic mechanism. Biochem J (1978) 1.24

Cryoenzymology of papain: reaction mechanism with an ester substrate. Biochemistry (1978) 1.16

Inhibition of bovine factor IXa and factor Xabeta by antithrombin III. Biochemistry (1976) 1.16

Convergence of active center geometries. Biochemistry (1977) 1.14

Intramolecular inhibition by enzyme of site-specific modification reactions can mask pKa values characteristic of the reaction pathway: do the side chains of aspartic acid-158 and lysine-156 of papain form an ion-pair? [proceedings]. Biochem Soc Trans (1978) 1.09

The importance of the conformation of the tetrahedral intermediate for the alpha-chymotrypsin-catalyzed hydrolysis of peptide substrates. FEBS Lett (1975) 0.96

Evidence for a rate-limiting conformation change in the catalytic steps of the ficin and papain-catalysed hydrolyses of benzyloxycarbonyl-L-lysine p-nitrophenyl ester. Eur J Biochem (1973) 0.92

Thermodynamics of binding to native alpha-chymotrypsin and to forms of alpha-chymotrypsin in which catalytically essential residues are modified; a study of "productive" and "nonproductive" associations. Biochemistry (1977) 0.92

Stereoelectronic control in carbon-oxygen and phosphorus-oxygen bond breaking processes. Ab initio calculations and speculations on the mechanism of action of ribonuclease A, staphylococcal nuclease, and lysozyme. J Am Chem Soc (1977) 0.91

Inhibition of papain by N-acyl-aminoacetaldehydes and N-acyl-aminopropanones. Evidence for hemithioacetal formation by a cross-saturation technique in nuclear-magnetic resonance spectroscopy. Eur J Biochem (1977) 0.90

Kinetics of the action of papain on fluorescent peptide substrates. Biochemistry (1976) 0.88

Papain-catalyzed reactions of esters with alcohols. The nature of the rate-determining step. Biochemistry (1967) 0.81

The kinetics of papain- and ficin-catalysed hydrolyses in the presence of alcohols. Biochem J (1966) 0.79

Conformational changes in papain during catalysis and ligand binding. Biochemistry (1974) 0.79

Reactions of papain and of low-molecular-weight thiols with some aromatic disulphides. 2,2'-Dipyridyl disulphide as a convenient active-site titrant for papain even in the presence of other thiols. Biochem J (1973) 3.33

A reporter group delivery system with both absolute and selective specificity for thiol groups and an improved fluorescent probe containing the 7-nitrobenzo-2-oxa-1,3-diazole moiety. Biochem J (1975) 3.17

Covalent chromatography. Preparation of fully active papain from dried papaya latex. Biochem J (1973) 2.79

Reactivities of the various protonic states in the reactions of papain and of L-cysteine with 2,2'- and with 4,4'- dipyridyl disulphide: evidence for nucleophilic reactivity in the un-ionized thiol group of the cysteine-25 residue of papain occasioned by its interaction with the histidine-159-asparagine-175 hydrogen-bonded system. Biochem J (1972) 2.65

Preparation of fully active ficin from Ficus glabrata by covalent chromatography and characterization of its active centre by using 2,2'-depyridyl disulphide as a reactivity probe. Biochem J (1976) 2.53

Characterization of the papain active centre by using two-protonic-state electrophiles as reactivity probes. Evidence for nucleophilic reactivity in the un-interrupted cysteine-25-histidine-159 interactive system. Biochem J (1978) 2.21

A necessary modification to the preparation of papain from any high-quality latex of Carica papaya and evidence for the structural integrity of the enzyme produced by traditional methods. Biochem J (1979) 2.20

Specific covalent modification of thiols: applications in the study of enzymes and other biomolecules. Int J Biochem (1979) 2.11

PH-dependence of the steady-state rate of a two-step enzymic reaction. Biochem J (1976) 2.08

The equilibrium assumption is valid for the kinetic treatment of most time-dependent protein-modification reactions. Biochem J (1979) 1.82

4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole as a reactivity probe for the investigation of the thiol proteinases. evidence that ficin and bromelain may lack carboxyl groups conformationally equivalent to that of aspartic acid-158 of papain. Biochem J (1976) 1.77

The pH-dependence of second-order rate constants of enzyme modification may provide free-reactant pKa values. Biochem J (1977) 1.73

Two-protonic-state electrophiles as probes of enzyme mechanisms. Methods Enzymol (1982) 1.70

Covalent chromatography by thiol-disulfide interchange. Methods Enzymol (1974) 1.61

Differences in the interaction of the catalytic groups of the active centres of actinidin and papain. Rapid purification of fully active actinidin by covalent chromatography and characterization of its active centre by use of two-protonic-state reactivity probes. Biochem J (1981) 1.60

A spectrophotometric method for the detection of contaminant chymopapains in preparations of papain. Selective modification of one type of thiol group in the chymopapains by a two-protonic-state reagent. Biochem J (1978) 1.52

Kinetics of the reversible reaction of papain with 5,5'-dithiobis-(2-nitrobenzoate) dianion: evidence for nucleophilic reactivity in the un-ionized thiol group of cysteine-25 and for general acid catalysis by histidine-159 of the reaction of the 5-mercapto-2-nitrobenzoate dianion with the papain-5-mercapto-2-nitrobenzoate mixed disulphide. Biochem J (1972) 1.52

The case for assigning a value of approximately 4 to pKa-i of the essential histidine-cysteine interactive systems of papain, bromelain and ficin. FEBS Lett (1975) 1.50

Kinetics of the hydrolysis of N-benzoyl-L-serine methyl ester catalysed by bromelain and by papain. Analysis of modifier mechanisms by lattice nomography, computational methods of parameter evaluation for substrate-activated catalyses and consequences of postulated non-productive binding in bromelain- and papain-catalysed hydrolyses. Biochem J (1974) 1.47

In defence of the general validity of the Cha method of deriving rate equations. The importance of explicit recognition of the thermodynamic box in enzyme kinetics. Biochem J (1992) 1.45

Evidence that the active centre of chymopapain A is different from the active centres of some other cysteine proteinases and that the Brønsted coefficient (beta nuc.) for the reactions of thiolate anions with 2,2'-dipyridyl disulphide may be decreased by reagent protonation. Biochem J (1980) 1.44

The mutability of stem bromelain: evidence for perturbation by structural transitions of the parameters that characterize the reaction of the essential thiol group of bromelain with 2,2'-dipyridyl disulphide. Biochem J (1972) 1.42

Evidence for a two-state transition in papain that may have no close analogue in ficin. Differences in the disposition of cationic sites and hydrophobic binding areas in the active centres of papain and ficin. Biochem J (1980) 1.39

The activity of the tissue inhibitors of metalloproteinases is regulated by C-terminal domain interactions: a kinetic analysis of the inhibition of gelatinase A. Biochemistry (1993) 1.36

A re-evaluation of the nomenclature of the cysteine proteinases of Carica papaya and a rational basis for their identification. Biochem J (1983) 1.35

Benzofuroxan as a thiol-specific reactivity probe. Kinetics of its reactions with papain, ficin, bromelain and low-molecular-weight thiols. Biochem J (1977) 1.31

Differences in the chemical and catalytic characteristics of two crystallographically 'identical' enzyme catalytic sites. Characterization of actinidin and papain by a combination of pH-dependent substrate catalysis kinetics and reactivity probe studies targeted on the catalytic-site thiol group and its immediate microenvironment. Biochem J (1987) 1.30

A classical enzyme active center motif lacks catalytic competence until modulated electrostatically. Biochemistry (1997) 1.26

Preparation of cathepsins B and H by covalent chromatography and characterization of their catalytic sites by reaction with a thiol-specific two-protonic-state reactivity probe. Kinetic study of cathepsins B and H extending into alkaline media and a rapid spectroscopic titration of cathepsin H at pH 3-4. Biochem J (1985) 1.26

The reaction of papain with Ellman's reagent (5,5'-dithiobis- (2-nitrobenzoate) dianion). Biochem J (1972) 1.25

Rapid type 2 molybdenum(V) electron-paramagnetic resonance signals from xanthine oxidase and the structure of the active centre of the enzyme. Biochem J (1980) 1.24

Mechanism of the reaction of papain with substrate-derived diazomethyl ketones. Implications for the difference in site specificity of halomethyl ketones for serine proteinases and cysteine proteinases and for stereoelectronic requirements in the papain catalytic mechanism. Biochem J (1978) 1.24

Characterization of papaya peptidase A as a cysteine proteinase of Carica papaya L. with active-centre properties that differ from those of papain by using 2,2'-dipyridyl disulphide and 4-chloro-7-nitrobenzofurazan as reactivity probes. Use of two-protonic-state electrophiles in the identification of catalytic-site thiol groups. Biochem J (1982) 1.24

A general framework of cysteine-proteinase mechanism deduced from studies on enzymes with structurally different analogous catalytic-site residues Asp-158 and -161 (papain and actinidin), Gly-196 (cathepsin B) and Asn-165 (cathepsin H). Kinetic studies up to pH 8 of the hydrolysis of N-alpha-benzyloxycarbonyl-L-arginyl-L-arginine 2-naphthylamide catalysed by cathepsin B and of L-arginine 2-naphthylamide catalysed by cathepsin H. Biochem J (1985) 1.23

The preparation and some properties of bromelain covalently attached to O-(carboxymethyl)-cellulose. Eur J Biochem (1968) 1.22

A marked gradation in active-centre properties in the cysteine proteinases revealed by neutral and anionic reactivity probes. Reactivity characteristics of the thiol groups of actinidin, ficin, papain and papaya peptidase A towards 4,4'-dipyridyl disulphide and 5,5'-dithiobis-(2-nitrobenzoate) dianion. Biochem J (1983) 1.21

13C NMR of cyanylated flavodoxin from Megasphaera elsdenii and of thiocyanate model compounds. Biochemistry (1992) 1.20

Reactivities of neutral and cationic forms of 2,2'-dipyridyl disulphide towards thiolate anions. Detection of differences between the active centres of actinidin, papain and ficin by a three-protonic-state reactivity probe. Biochem J (1979) 1.19

Effects of conformational selectivity and of overlapping kinetically influential ionizations on the characteristics of pH-dependent enzyme kinetics. Implications of free-enzyme pKa variability in reactions of papain for its catalytic mechanism. Biochem J (1983) 1.19

Natural structural variation in enzymes as a tool in the study of mechanism exemplified by a comparison of the catalytic-site structure and characteristics of cathepsin B and papain. pH-dependent kinetics of the reactions of cathepsin B from bovine spleen and from rat liver with a thiol-specific two-protonic-state probe (2,2'-dipyridyl disulphide) and with a specific synthetic substrate (N-alpha-benzyloxycarbonyl-L-arginyl-L-arginine 2-naphthylamide). Biochem J (1984) 1.19

Immobilization of urease by thiol-disulphide interchange with concomitant purification. Eur J Biochem (1974) 1.19

A convenient method of preparation of high-activity urease from Canavalia ensiformis by covalent chromatography and an investigation of its thiol groups with 2,2'-dipyridyl disulphide as a thiol titrant and reactivity probe. Biochem J (1976) 1.19

Evaluation of benzofuroxan as a chromophoric oxidizing agent for thiol groups by using its reactions with papain, ficin, bromelain and low-molecular-weight thiols. Biochem J (1977) 1.18

Propapain and its conversion to papain: a new type of zymogen activation mechanism involving intramolecular thiol-disulphide interchange. Nat New Biol (1973) 1.17

Fresh non-fruit latex of Carica papaya contains papain, multiple forms of chymopapain A and papaya proteinase omega. Biochem J (1985) 1.12

The pre-eminence of k(cat) in the manifestation of optimal enzymic activity delineated by using the Briggs-Haldane two-step irreversible kinetic model. Biochem J (1976) 1.12

Investigation of the catalytic site of actinidin by using benzofuroxan as a reactivity probe with selectivity for the thiolate-imidazolium ion-pair systems of cysteine proteinases. Evidence that the reaction of the ion-pair of actinidin (pKI 3.0, pKII 9.6) is modulated by the state of ionization of a group associated with a molecular pKa of 5.5. Biochem J (1983) 1.11

13C NMR study of the ionizations within a trypsin-chloromethyl ketone inhibitor complex. Biochemistry (1985) 1.10

A general kinetic equation for multihydronic state reactions and rapid procedures for parameter evaluation. Biochem Soc Trans (1990) 1.09

Intramolecular inhibition by enzyme of site-specific modification reactions can mask pKa values characteristic of the reaction pathway: do the side chains of aspartic acid-158 and lysine-156 of papain form an ion-pair? [proceedings]. Biochem Soc Trans (1978) 1.09

Structure-function relationships in the cysteine proteinases actinidin, papain and papaya proteinase omega. Three-dimensional structure of papaya proteinase omega deduced by knowledge-based modelling and active-centre characteristics determined by two-hydronic-state reactivity probe kinetics and kinetics of catalysis. Biochem J (1991) 1.08

pH-activity curves for enzyme-catalysed reactions in which the hydron is a product or reactant. Biochem J (1987) 1.08

A 13C-n.m.r. investigation of the ionizations within an inhibitor--alpha-chymotrypsin complex. Evidence that both alpha-chymotrypsin and trypsin stabilize a hemiketal oxyanion by similar mechanisms. Biochem J (1989) 1.06

The nature of the sulphur atom liberated from xanthine oxidase by cyanide. Evidence from e.p.r. spectroscopy after 35S substitution. Biochem J (1980) 1.06

Reactions of L-ergothioneine and some other aminothiones with2,2'-and 4,4'-dipyridyl disulphides and of L-ergothioneine with iodoacetamide. 2-Mercaptoimidazoles, 2- and 4-thiopyridones, thiourea and thioacetamide as highly reactive neutral sulphur nucleophils. Biochem J (1974) 1.05

The nature of the perturbation of the michaelis constant of the bromelain-catalysed hydrolysis of alpha-N-benzoyl-L-arginine ethyl ester consequent upon attachment of bromelain to O-(carboxymethyl)-cellulose. Eur J Biochem (1968) 1.05

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. Biochem J (1989) 1.04

A polyclonal antibody preparation with Michaelian catalytic properties. Biochem J (1991) 1.03

Evolution of enzyme catalytic power. Characteristics of optimal catalysis evaluated for the simplest plausible kinetic model. Biochem J (1977) 1.02

'Chymopapain S' is chymopapain A. Biochem J (1984) 1.02

Biochemical and X-ray crystallographic studies on shikimate kinase: the important structural role of the P-loop lysine. Protein Sci (2001) 1.02

Ionization characteristics of the Cys-25/His-159 interactive system and of the modulatory group of papain: resolution of ambiguity by electronic perturbation of the quasi-2-mercaptopyridine leaving group in a new pyrimidyl disulphide reactivity probe. Biochem J (1993) 1.01

Enzymatically active papain preferentially induces an allergic response in mice. Biochem Biophys Res Commun (1998) 1.01

D-3-hydroxybutyrate dehydrogenase from Rhodopseudomonas spheroides. Kinetic mechanism from steady-state kinetics of the reaction catalysed by the enzyme in solution and covalently attached to diethylaminoethylcellulose. Biochem J (1973) 1.01

Comparative studies on the 5-aminolaevulinic acid dehydratases from Pisum sativum, Escherichia coli and Saccharomyces cerevisiae. Biochem J (1996) 0.99

Differences between the electric fields of the catalytic sites of papain and actinidin detected by using the thiol-located nitrobenzofurazan label as a spectroscopic reporter group. Biochem J (1984) 0.99

Evidence for a close similarity in the catalytic sites of papain and ficin in near-neutral media despite differences in acidic and alkaline media. Kinetics of the reactions of papain and ficin with chloroacetate. Biochem J (1982) 0.98

Appendix: Analysis of pH-dependent kinetics in up to four reactive hydronic states. Biochem J (1988) 0.98

A 13C-n.m.r. investigation of ionizations within a trypsin-inhibitor complex. Evidence that the pKa of histidine-57 is raised by interaction with the hemiketal oxyanion. Biochem J (1985) 0.97

Clarification of the pH-dependent kinetic behaviour of papain by using reactivity probes and analysis of alkylation and catalysed acylation reactions in terms of multihydronic state models: implications for electrostatics calculations and interpretation of the consequences of site-specific mutations such as Asp-158-Asn and Asp-158-Glu. Biochem J (1993) 0.97

The highly electrophilic character of 4-chloro-7-nitrobenzofurazan and possible consequences for its application as a protein-labelling reagent. Biochem J (1977) 0.97

Characterization of the hydrolytic activity of a polyclonal catalytic antibody preparation by pH-dependence and chemical modification studies: evidence for the involvement of Tyr and Arg side chains as hydrogen-bond donors. Biochem J (1997) 0.97

Ionization characteristics and chemical influences of aspartic acid residue 158 of papain and caricain determined by structure-related kinetic and computational techniques: multiple electrostatic modulators of active-centre chemistry. Biochem J (2000) 0.97

Preparation and characterization of enzymes from spray-dried papaya (Carica papaya) latex [proceedings]. Biochem Soc Trans (1978) 0.95

Evidence that the lack of high catalytic activity of thiolsubtilisin towards specific substrates may be due to an inappropriately located proton-distribution system. Demonstration of highly nucleophilic character of the thiol group of thiolsubtilisin in the catalytically relevant ionization state of the active centre by use of a two-protonic-state reactivity probe. Biochem J (1981) 0.94

Polyclonal-antibody-catalysed hydrolysis of an aryl nitrophenyl carbonate. Biochem Soc Trans (1990) 0.94

Characterization of the electrostatic perturbation of a catalytic site (Cys)-S-/(His)-Im+H ion-pair in one type of serine proteinase architecture by kinetic and computational studies on chemically mutated subtilisin variants. J Mol Biol (1996) 0.93

The interplay of electrostatic fields and binding interactions determining catalytic-site reactivity in actinidin. A possible origin of differences in the behaviour of actinidin and papain. Biochem J (1989) 0.92

Catalytic antibody activity elicited by active immunisation. Evidence for natural variation involving preferential stabilization of the transition state. Eur J Biochem (1993) 0.92

Variation in aspects of cysteine proteinase catalytic mechanism deduced by spectroscopic observation of dithioester intermediates, kinetic analysis and molecular dynamics simulations. Biochem J (2001) 0.91

A re-appraisal of the structural basis of stereochemical recognition in papain. Insensitivity of binding-site-catalytic-site signalling to P2-chirality in a time-dependent inhibition. Biochem J (1990) 0.90

Coupling of [33S]sulphur to molybdenum(V) in different reduced forms of xanthine oxidase. Biochem J (1981) 0.90

The interplay of electrostatic and binding interactions determining active centre chemistry and catalytic activity in actinidin and papain. Biochem J (1989) 0.90

Chemical evidence for the pH-dependent control of ion-pair geometry in cathepsin B. Benzofuroxan as a reactivity probe sensitive to differences in the mutual disposition of the thiolate and imidazolium components of cysteine proteinase catalytic sites. Biochem J (1986) 0.90