scholarly journals Bovine pepsinogens and pepsins. The sequence around a reactive aspartyl residue

1971 ◽  
Vol 124 (4) ◽  
pp. 673-676 ◽  
Author(s):  
Patricia A. Meitner
Keyword(s):  
Methyl Ester ◽  
Aspartic Acid ◽  
Specific Inhibitor ◽  
Enzymic Activity ◽  
Active Centre ◽  
Aspartic Acid Residue ◽  
Porcine Pepsin ◽  
Simultaneous Loss ◽  
Aspartyl Residue

The specific inhibitor, N-diazoacetylnorleucine methyl ester reacts stoicheiometrically with bovine pepsin resulting in a simultaneous loss of all enzymic activity. A peptide containing a modified aspartyl group was isolated from bovine pepsin labelled with 14C-labelled inhibitor. The aspartic acid residue is presumed to be part of the active centre and is in the same heptapeptide sequence as in porcine pepsin: Ile-Val-Asp-Thr-Gly-Thr-Ser.

scholarly journals An active-site peptide from pepsin C

1971 ◽  
Vol 123 (1) ◽  
pp. 75-82 ◽  
Author(s):  
J. Kay ◽  
A. P. Ryle
Keyword(s):  
Methyl Ester ◽  
Aspartic Acid ◽  
Active Site ◽  
Carboxyl Group ◽  
Active Site Residue ◽  
Aspartic Acid Residue ◽  
Porcine Pepsin ◽  
Ph Values ◽  
Complete Inactivation ◽  
Active Site Sequence

Porcine pepsin C is inactivated rapidly and irreversibly by diazoacetyl-dl-norleucine methyl ester in the presence of cupric ions at pH values above 4.5. The inactivation is specific in that complete inactivation accompanies the incorporation of 1mol of inhibitor residue/mol of enzyme and evidence has been obtained to suggest that the reaction occurs with an active site residue. The site of reaction is the β-carboxyl group of an aspartic acid residue in the sequence Ile-Val-Asp-Thr. This sequence is identical with the active-site sequence in pepsin and the significance of this in terms of the different activities of the two enzymes is discussed.

scholarly journals An aspartic acid residue at the active site of pepsin. The isolation and sequence of the heptapeptide

1969 ◽  
Vol 113 (2) ◽  
pp. 377-386 ◽  
Author(s):  
R. S. Bayliss ◽  
J. R. Knowles ◽  
Grith B. Wybrandt
Keyword(s):  
Methyl Ester ◽  
Aspartic Acid ◽  
Active Site ◽  
Irreversible Inhibitor ◽  
Aspartic Acid Residue ◽  
Phenylalanine Methyl Ester

Pepsin reacts stoicheiometrically with the active-site-directed irreversible inhibitor N-diazoacetyl-l-phenylalanine methyl ester, with concomitant loss of all proteolytic and peptidolytic activity. The reagent esterifies a unique aspartic acid residue in pepsin, which is in the sequence:Ile-Val-Asp-Thr-Gly-Thr-Ser

The Inactivation of Penicillopepsin with l,2-Epoxy-3-(p-nitrophenoxy)propane, an Active-Site Directed Reagent

1974 ◽  
Vol 52 (11) ◽  
pp. 1018-1023 ◽  
Author(s):  
G. Mains ◽  
T. Hofmann
Keyword(s):  
Methyl Ester ◽  
Aspartic Acid ◽  
Active Site ◽  
Side Chain ◽  
Porcine Pepsin ◽  
Protein Inactivation ◽  
Pepsin Inhibitor

Penicillopepsin was fully inactivated by the pepsin inhibitor 1,2-epoxy-3-(p-nitrophenoxy) propane, and 1.3 ± 0.3 mol of reagent became associated with each mole of protein. Inactivation was more rapid at pH 3.0 than at pH 6.0. Approximately 1 equivalent of the bound reagent was esterified to an aspartic acid side chain. Enzyme previously inactivated with diazoacetylnorleucine methyl ester did not react with the epoxide; and enzyme that was first inactivated with the epoxide did not react with the diazo inhibitor. The results add further evidence for the enzymatic similarity of porcine pepsin and penicillopepsin.

Amino acid sequence around the active site aspartic acid in penicillopepsin

1970 ◽  
Vol 48 (9) ◽  
pp. 1014-1016 ◽  
Author(s):  
J. Šodek ◽  
T. Hofmann
Keyword(s):  
Amino Acid ◽  
Methyl Ester ◽  
Amino Acid Sequence ◽  
Aspartic Acid ◽  
Strong Evidence ◽  
Active Site ◽  
Ester Group ◽  
Acid Proteinase ◽  
Penicillium Janthinellum ◽  
Porcine Pepsin

Penicillopepsin, the acid proteinase of Penicillium janthinellum, was specifically inactivated with diazoacetylnorleucine methyl ester. The peptide containing the glycollylnorleucine methyl ester group was isolated from a peptic digest. The amino acid sequence was found to be Ile∙Ala∙β(glycollyl-Nle OMe)-Asp∙Thr∙Gly∙Thr∙Thr∙Leu and is thus almost identical with the active site peptide of porcine pepsin: Ile∙Val∙Asp∙Thr∙Gly∙Thr∙Ser. This finding provides strong evidence for an evolutionary homology between penicillopepsin and porcine pepsin.

scholarly journals 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

1980 ◽  
Vol 191 (3) ◽  
pp. 707-718 ◽  
Author(s):  
K Brocklehurst ◽  
J P G Malthouse
Keyword(s):  
Aspartic Acid ◽  
Catalytic Mechanism ◽  
Striking Difference ◽  
Compound I ◽  
Active Centre ◽  
Aspartic Acid Residue ◽  
Wide Range ◽  
Cationic Site ◽  
Hydrophobic Binding ◽  
Kinetics Of

The kinetics of the reactions of the active-centre thiol groups of papain (EC 3.4.22.2) and ficin (EC 3.4.22.3) with the two-protonic-state reactivity probes 2,2′-dipyridyl disulphide, n-propyl 2-pyridyl disulphide and 4-(N-aminoethyl 2′-pyridyl disulphide)- 7-nitrobenzo-2-oxa-1,3-diazole (compound I) were studied over a wide range of pH. Differences between the reactivities of ficin and papain towards the cationic forms of the alkyl 2-pyridyl disulphide probes suggest that ficin contains a cationic site without exact analogue in papain, and the striking difference in the shapes of the pH-rate profiles for the reactions of the two enzymes with compound (1) suggests differences in the mobilities or dispositions of the active-centre histidine imidazole groups with respect to relevant hydrophobic binding areas. The evidence from reactivity-probe studies that the papain catalytic mechanism involves substantial repositioning of the active-centre imidazole group during the catalytic act does not apply also to ficin. If ficin contains an aspartic acid residue analogous to aspartic acid-158 in papain, the pKa of its carboxy group is probably significantly lower than the pKa of the analogous group in papain.

Localization of the aspartic acid residue present in the active center of porcine pepsin

1973 ◽  
Vol 9 (4) ◽  
pp. 540-541
Author(s):  
Ya. F. Kovalishin ◽  
V. I. Ostoslavskaya ◽  
V. M. Stepanov
Keyword(s):  
Aspartic Acid ◽  
Active Center ◽  
Aspartic Acid Residue ◽  
Porcine Pepsin

Isolation and characterization of a peptide derived from the active site of chicken pepsin

1980 ◽  
Vol 45 (7) ◽  
pp. 2131-2134 ◽  
Author(s):  
Helena Keilová ◽  
Vladimír Kostka ◽  
Miroslav Baudyš
Keyword(s):  
Amino Acid ◽  
Methyl Ester ◽  
Amino Acid Composition ◽  
Aspartic Acid ◽  
Acid Composition ◽  
Active Site ◽  
Its Sequence ◽  
Aspartic Acid Residue ◽  
Isolation And Characterization

A peptide was isolated from chicken pepsin which contains the aspartic acid residue reacting with diazoacetyl-D,L-norleucine methyl ester in the presence of Cu2+ -ions. The peptide is N-terminated with isoleucine and contains (besides isoleucine) valine, aspartic acid, two threonines, serine, and leucine. In concurrent experiments a peptide of the same composition was isolated from the thermolysin digest of chicken pepsin and its sequence determined as Ile-Val-Asp-Thr-Gly-Thr-Ser-Leu. Since both peptides have entirely identical amino acid composition and other characteristics, the sequenced peptide corresponds to the peptide isolated from the active site of the enzyme.

scholarly journals Structure and enzymic activity of ribonuclease-A esterified at glutamic acid-49 and aspartic acid-53

1978 ◽  
Vol 173 (3) ◽  
pp. 821-830 ◽  
Author(s):  
A. Seetharama Acharya ◽  
Belur N. Manjula ◽  
Paul J. Vithayathil
Keyword(s):  
Methyl Ester ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Spectral Characteristics ◽  
Dimethyl Ester ◽  
Limited Proteolysis ◽  
Ribonuclease A ◽  
Enzymic Activity ◽  
S Protein ◽  
Hydrolysis Of

The dimethyl ester of bovine pancreatic ribonuclease-A (dimethyl RNAase-A), the initial product of esterification of RNAase-A in anhydrous methanolic HCl, was isolated in a homogeneous form. The two carboxy functions esterified in this derivative are those of glutamic acid-49 and aspartic acid-53. There were no changes in the u.v.-absorption spectral characteristics, the accessibility of the methionine residues, the resistance of the protein to proteolysis by trypsin and the antigenic behaviour of RNAase-A as a result of the esterification of these two carboxy groups. Dimethyl RNAase-A exhibited only 65% of the specific activity of RNAase-A, but still had the same Km value for both RNA and 2′:3′-cyclic CMP. However, the Vmax. was decreased by about 35%. On careful hydrolysis of the methyl ester groups at pH9.5, dimethyl RNAase-A was converted back into RNAase-A. Limited proteolysis of dimethyl RNAase-A by subtilisin resulted in the formation of an active RNAase-S-type derivative, namely dimethyl RNAase-S, which was chromatographically distinct from dimethyl RNAase-A and had very nearly the same enzymic activity as dimethyl RNAase-A. Fractionation of dimethyl RNAase-S by trichloroacetic acid yielded dimethyl RNAase-S-protein and dimethyl RNAase-S-peptide, both of which were inactive by themselves but regenerated dimethyl RNAase-S when mixed together. Dimethyl RNAase-A-peptide was identical with RNAase-S-peptide. RNAase-S-protein could be generated from dimethyl RNAase-S-protein by careful hydrolysis of the methyl ester groups at pH9.5. The interaction of dimethyl RNAase-S-protein with RNAase-S-peptide appears to be about 4-fold weaker than that between the RNAase-S-protein and RNAase-S-peptide. Conceivably, the binding of the S-peptide ‘tail’ of dimethyl RNAase-A with the remainder of the molecule is similarly weaker than that in RNAase-A, and this brings about subtle changes in the geometrical orientation of the active-site amino acid residues of these modified methyl ester derivatives. It is suggested that these changes could be responsible for the generation of the catalytically less-efficient RNAase-A and RNAase-S molecules (dimethyl RNAase-A and dimethyl RNAase-S respectively).

scholarly journals Capsid assembly in a family of animal viruses primes an autoproteolytic maturation that depends on a single aspartic acid residue.

1994 ◽  
Vol 269 (18) ◽  
pp. 13680-13684
Author(s):  
A. Zlotnick ◽  
V.S. Reddy ◽  
R. Dasgupta ◽  
A. Schneemann ◽  
W.J. Ray ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Capsid Assembly ◽  
Aspartic Acid Residue
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