title: Preparation of chromophoric substrates for the glutamoyl specific staphylococcal protease.
abstract: The synthesis of chromophoric substrates allowing an accurate determination of the staphylococcal protease activity is described. BOC-L-Glu-OPh, BOC-L-Phe-L-Glu-OPh, BOC-L-Ala-L-Glu-OPh, BOC-L-Ser-L-Glu-OPh and Z-L-Glu-pNA were prepared. Kinetic parameters of the staphyloccal protease-catalysed hydrolyses of these substrates are compared. In every case the dipeptide ester substrates lead to a lower catalytic efficiency (kcat/Km ratio), compared with either BOC-L-Glu-OPh or Z-L-Glu-OPh, mainly because of an increase in the Km value. Like other serine proteinases, the staphylococcal protease exhibits a high ratio of eeterase to peptidase activity, the kcat/Km ratio being 2.6 X 10(5)-fold higher with the Z-L-Glu-OPh than with the Z-L-Glu-pNA.
mesh_terms: D000813:Anilides / Q000138:chemical synthesis; D004396:Coloring Agents / Q000138:chemical synthesis* / Q000378:metabolism; D004952:Esters / Q000138:chemical synthesis; D007700:Kinetics; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology*
chemical_list: D000813:Anilides; D004396:Coloring Agents; D004952:Esters; D010447:Peptide Hydrolases