You must cleave the following peptide into smaller fragments. Which of the proteases listed in Table 5-4 would be likely to yield the most fragments? The fewest?
NMTQGRCKPVNTFVHEPLVDVQNVCFKE

Transcribed Image Text:

TABLE 5-4 Specificities of Various Endopeptidases R-1 O Enzyme Trypsin Chymotrypsin Elastase Thermolysin Pepsin Endopeptidase V8 Source Bovine pancreas Bovine pancreas Bovine pancreas -NH-CHC Bacillus thermoproteolyticus Bovine gastric mucosa Staphylococcus aureus Scissile peptide bond R NHCH i C Specificity R1 positively charged residues: Arg, Lys; R = Pro R-1 = Glu R1 = bulky hydrophobic residues: Phe, Trp, Tyr; R, Pro R-1 = small neutral residues: Ala, Gly Ser, Val; R, Pro R = Ile, Met, Phe, Trp, Tyr, Val; R-1 Pro R,= Leu, Phe, Trp, Tyr; R-1 Pro Comments Highly specific Cleaves more slowly for R-1 Asn, His, Met, Leu Occasionally cleaves at R,, = Ala, Asp, His, Thr; heat stable Also others; quite nonspecific; pH optimum = 2