Peptide bond hydrolysis is performed by a family of enzymes known as serine proteases. The name is derived from a highly conserved serine residue in these enzymes that is critical for enzyme function. One member of this enzyme class is chymotrypsin, which preferentially cleaves proteins at residue sites with hydrophobic side chains such as phenylalanine, leucine, and tyrosine. For example, N-benzoyl-tyrosylamide (NBT) and N-acetyl-tyrosylamide (NAT) are cleaved by chymotrypsin.

a. The cleavage of NBT by chymotrypsin was studied and the following reaction rates were measured as a function of substrate concentration:

Use these data to determine K_m and Rate _max for chymotrypsin with NBT as the substrate

b. The cleavage of NAT was also studied and the following reaction rates versus substrate concentration were measured:

Use these data to determine Km and rate _max for chymotrypsin with NAT as the substrate.

Transcribed Image Text:

нн нн -C-N-C-C-NH, Нас —С—N—с -С-NH2 CH2 CH2 Он Он N-benzoyl-tyrosylamide (NBT) N-acetyl-tyrosylamide (NAT) NBT] (mM) 1.00 2.00 4.00 6.00 8.00 Rateg(mM s) 0.062 0.107 0.040 0.082 0.099