Pepsin as a catalyst for peptide synthesis: formation of peptide bonds not typical for pepsin substrate specificity.
Porcine pepsin in water solutions containing 15-28% of dimethylformamide at pH 5 and 20-37 degrees C catalysed the formation of peptide bonds between Z-Ala-Ala-Phe-OH and various amino acid or peptide derivatives. Substrate binding subsite S1' of pepsin demonstrated broad specificity in these reactions but revealed a certain preference for hydrophobic amino acid residues, including non-proteinous homophenylalanine, p-nitrophenylalanine, S-methylcysteine, as well as for those that contained, in addition to the hydrophobic elements, a group capable of donating a hydrogen bond, e.g. o-nitrotyrosine. This observation increases the range of peptides that might be prepared by pepsin-catalysed synthesis.
Chemistry Department of Damietta, Faculty of Science, Mansoura University, Egypt.
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CA
Malak
D000595:Amino Acid Sequence; D002384:Catalysis; D010434:Pepsin A / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000138:chemical synthesis* / Q000378:metabolism; D013379:Substrate Specificity; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism
D010455:Peptides; D014443:Tyrosine; D014364:Tryptophan; D010434:Pepsin A