Aspartic acid 214 in Citrobacter freundii tyrosine phenol-lyase ensures sufficient C–H-acidity of the external aldimine intermediate and proper orientation of the cofactor at the active site

2006 ◽  
Vol 1764 (7) ◽  
pp. 1268-1276 ◽  
Author(s):  
T.V. Demidkina ◽  
N.G. Faleev ◽  
A.I. Papisova ◽  
N.P. Bazhulina ◽  
V.V. Kulikova ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Active Site ◽  
Citrobacter Freundii ◽  
Tyrosine Phenol Lyase ◽  
Proper Orientation

The role of active site tyrosine 58 in Citrobacter freundii methionine γ-lyase

2015 ◽  
Vol 1854 (9) ◽  
pp. 1220-1228 ◽  
Author(s):  
Natalya V. Anufrieva ◽  
Nicolai G. Faleev ◽  
Elena A. Morozova ◽  
Natalia P. Bazhulina ◽  
Svetlana V. Revtovich ◽  
...  
Keyword(s):  
Active Site ◽  
Citrobacter Freundii ◽  
Active Site Tyrosine

scholarly journals Site-directed mutagenesis of dicarboxylic acids near the active site of Bacillus cereus 5/B/6 β-lactamase II

1991 ◽  
Vol 276 (2) ◽  
pp. 401-404 ◽  
Author(s):  
H M Lim ◽  
R K Iyer ◽  
J J Pène
Keyword(s):  
Bacillus Cereus ◽  
Aspartic Acid ◽  
Carboxy Group ◽  
Active Site ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Aspartic Acid Residue ◽  
Beta Lactamase Ii

An amino acid residue functioning as a general base has been proposed to assist in the hydrolysis of beta-lactam antibiotics by the zinc-containing Bacillus cereus beta-lactamase II [Bicknell & Waley (1985) Biochemistry 24, 6876-6887]. Oligonucleotide-directed mutagenesis of cloned Bacillus cereus 5/B/6 beta-lactamase II was used in an ‘in vivo’ study to investigate the role of carboxy-group-containing amino acids near the active site of the enzyme. Substitution of asparagine for the wild-type aspartic acid residue at position 81 resulted in fully functional enzyme. An aspartic acid residue at position 90 is essential for beta-lactamase II to confer any detectable ampicillin and cephalosporin C resistance to Escherichia coli. Conversion of Asp90 into Asn90 or Glu90 lead to the synthesis of inactive enzyme, suggesting that the spatial position of the beta-carboxy group of Asp90 is critical for enzyme function.

scholarly journals Substitution of aspartic acid-217 of Citrobacter freundii cephalosporinase and properties of the mutant enzymes

FEBS Letters ◽  
1990 ◽  
Vol 264 (2) ◽  
pp. 211-214 ◽  
Author(s):  
Kikuo Tsukamoto ◽  
Run Kikura ◽  
Reiko Ohno ◽  
Tetsuo Sawai
Keyword(s):  
Aspartic Acid ◽  
Citrobacter Freundii

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.

scholarly journals Aspartic acid-121 functions at the active site of bovine pancreatic ribonuclease

FEBS Letters ◽  
1984 ◽  
Vol 171 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Mary S. Stern ◽  
Marilynn S. Doscher
Keyword(s):  
Aspartic Acid ◽  
Active Site ◽  
Pancreatic Ribonuclease
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