title: Engineering of the active site of human lysozyme: conversion of aspartic acid 53 to glutamic acid and tyrosine 63 to tryptophan or phenylalanine.
abstract: Three human lysozymes containing a mutation either at Asp-53 to Glu or at Tyr-63 to Trp or Phe were synthesized and examined for their immunological and enzymatical activities in comparison with the native one. All mutants were immunologically indistinguishable from native human lysozyme. The [Trp63] and [Phe63] mutants catalysed the hydrolysis of Micrococcus lysodeikticus cell wall and glycol chitin effectively, while the [Glu53] mutant displayed very low activity toward M. lysodeikticus cells and no detectable activity toward glycol chitin.
mesh_terms: D000595:Amino Acid Sequence; D001224:Aspartic Acid; D002686:Chitin / Q000378:metabolism; D005818:Genetic Engineering; D005971:Glutamates; D018698:Glutamic Acid; D006801:Humans; D008837:Micrococcus; D009113:Muramidase / Q000138:chemical synthesis* / Q000235:genetics; D009154:Mutation; D010649:Phenylalanine; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014364:Tryptophan; D014443:Tyrosine
chemical_list: D005971:Glutamates; D002686:Chitin; D001224:Aspartic Acid; D018698:Glutamic Acid; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D009113:Muramidase