- Superiority of the carbamoylmethyl ester as an acyl donor for the kinetically controlled amide-bond formation mediated by α-chymotrypsin
-
The superiority of the carbamoylmethyl ester as an acyl donor for the α-chymotrypsin-catalysed kinetically controlled peptide-bond formation is demonstrated in the couplings of an inherently poor amino acid substrate, Ala, with various amino acid residues as amino components and in the couplings of non-protein amino acids such as halogenophenylalanines as carboxylic components. Furthermore, this approach is applied to the amide-bond formation between an amino acid residue and a chiral amine, which is highly diastereoselective.
- Miyazawa, Toshifumi,Ensatsu, Eiichi,Yabuuchi, Nobuhiro,Yanagihara, Ryoji,Yamada, Takashi
-
p. 390 - 395
(2007/10/03)
-
- Chemically modified "polar patch" mutants of subtilisin in peptide synthesis with remarkably broad substrate acceptance: Designing combinatorial biocatalysts
-
A significant enhancement of the applicability of the serine protease subtilisin Bacillus lentus (SBL) in peptide synthesis was achieved by using the strategy of combined site-directed mutagenesis and chemical modification to create chemically modified mu
- Matsumoto, Kazutsugu,Davis, Benjamin G.,Jones, J. Bryan
-
p. 4129 - 4137
(2007/10/03)
-
- Synthesis and biological evaluation of analogues of the antibiotic pantocin B
-
Strains of the bacteria Erwinia herbicola produce antibiotics that effectively control E. amylovora, the bacterial pathogen responsible for the plant disease fire blight. Pantocin B was the first of these antibiotics to be characterized, and a flexible sy
- Sutton,Clardy
-
p. 9935 - 9946
(2007/10/03)
-
- Glycosylation of the primary binding pocket of a subtilisin protease causes a remarkable broadening in stereospecificity in peptide synthesis
-
Site-selective glycosylation at position 166 at the base of the primary specificity S1 pocket in the serine protease subtilisin Bacillus lentus (SBL) created glycoproteins that are capable of catalyzing the coupling reactions of not only L- ami
- Matsumoto,Davis,Jones
-
p. 903 - 904
(2007/10/03)
-
- The total synthesis of pantocin B.
-
[reaction: see text] Pantocin B, an unusual antibiotic produced by Erwinia herbicola, effectively controls E. amylovora, the pathogen causing the plant disease fire blight. A total synthesis of pantocin B from L-alanine, glycine, and L-malic acid is repor
- Sutton,Clardy
-
p. 319 - 321
(2007/10/03)
-
- Expanded structural and stereospecificity in peptide synthesis with chemically modified mutants of subtilisin
-
Employing the strategy of combined site directed mutagenesis and chemical modification, we previously generated chemically modified mutant enzymes (CMMs) of subtilisin Bacillus lentus (SBL). We now report the use of these SBL-CMMs for peptide coupling rea
- Khumtaveeporn, Kanjai,DeSantis, Grace,Jones, J. Bryan
-
p. 2563 - 2572
(2007/10/03)
-
- PEPTIDE SYNTHESIS CATALYZED BY NATIVE PROTEINASE K IN WATER-MISCIBLE ORGANIC SOLVENTS WITH LOW WATER CONTENT
-
Rection of Ac-Tyr-OEt with HBr.Gly-NH2, catalysed by free proteinase K in various water-miscible organic solvents in the presence of triethylamine and 5 mol percent of water, was studied.Some aliphatic alcohols and acetonitrile proved to be suitable solvents.The effect of water content (2 percent - 20 percent) on the synthesis of Ac-Tyr-Gly-NH2 was studied using acetonitrile as solvent.Lowering of the water content to 5 percent or 2 percent led to almost 100 percent yield of the desired dipeptide; higher water content accelerated the reaction reducing at the same time the yield of Ac-Tyr-Gly-NH2 due to the concurrent hydrolysis of the ester Ac-Tyr-OEt.No reaction was observed in the absence of base (triethylamine), wereas an excess of base only retarded the reaction.The enzyme is capable of catalyzing the peptide bond synthesis with N-acylamino acids or N-acyl peptides as acylating components, which may contain all types of L-amino acid residues (except Pro) in the P1 position.However, the peptide bond synthesis depends strongly on the amino component composition, particularly on the amino acid residue in the P'1 position.Only amides of glycine and of hydrophillic amino acids were acylated with Ac-Tyr-OEt; amides of hydrophobic amino acids enter the reaction only reluctantly or not at al.The presence of Leu or Phe in position P'2 and Leu in position P'3 has not so negative effect on acylation of the amino component as has in presence in the P'1 position.The choice of protecting groups for the α-carboxyl of the amino component is restricted only to amide and in some cases its undesired enzymatic removal was observed.Unprotected peptides seem to be suitable amino components.
- Cerovsky, Vaclav,Martinek, Karel
-
p. 2027 - 2041
(2007/10/02)
-