Alteration of the substrate specificity of human lysozyme by site-specific intermolecular cross-linking.
Human lysozyme dimers were prepared by the intermolecular cross-linking of the monomer that contained the mutation of either Arg41 to Cys or Ala73 to Cys with a divalent maleimide compound. Among the three kinds of possible dimers only R41C-R41C dimer, in which the two catalytic clefts can come close to each other due to the proximity of the conjugation site to the active sites, turned out to be 2.3 times more specific to a polymer substrate, ethylene glycol chitin, as compared to an oligomer substrate, PNP-(GlcNAc)5. The result indicates that it is possible to alter the substrate specificity of an enzyme by artificially controlling the orientation of the active sites.
Muraki
M
M
Molecular Biology Department, National Institute of Bioscience and Human-Technology, Ibaraki, Japan.
Jigami
Y
Y
Harata
K
K
D000409:Alanine / Q000235:genetics; D001120:Arginine / Q000235:genetics; D001483:Base Sequence; D002240:Carbohydrate Sequence; D002686:Chitin / Q000031:analogs & derivatives / Q000378:metabolism; D002942:Circular Dichroism; D003432:Cross-Linking Reagents; D003545:Cysteine / Q000235:genetics; D005960:Glucosides / Q000378:metabolism; D006801:Humans; D008301:Maleimides; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009844:Oligosaccharides / Q000378:metabolism; D009994:Osmolar Concentration; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D003432:Cross-Linking Reagents; D005960:Glucosides; D008301:Maleimides; D009844:Oligosaccharides; C055288:4-nitrophenyl-N,N',N'',N''',N''''-pentaacetyl-beta-chitopentaoside; D002686:Chitin; C031610:glycolchitin; D001120:Arginine; D009113:Muramidase; D003545:Cysteine; D000409:Alanine