. doi:10.1046/j.1432-1033.2002.02997.xdesigned to maintain hydrophobicity and Gly, Ser, Asp andHis mutants to provide hydrophilicity. The catalytic roles ofCys341 in carboxypeptidase Y are examined by comparing the kinetic parameters. alsosuggest that Cys341 may be involved in the catalysis in a manner other than substrate binding. However, the precisetype of catalytic event affected by Cys341 remains unclear.X-ray crystallographic. Bio-Rad, Hercules, CA,USA. Bistris was obtained from Nacalai Tesque, Kyoto,Japan. All other chemicals were of reagent grade andobtained locally.Strains and plasmid DNA The plasmid pTSY3 containing...