Specificity of Papain-Catalyzed Transamidation Reactions

Beef liver esterase as a catalyst of acyl transfer to amino acid esters

“…That chymotrypsin can catalyze acyl transfer from suitable substrates to the -amino group of amino acid residues has long been known (Johnston et at., 1950b; Blau and Waley, 1954). Chymotrypsin, however, is much less effective as a catalyst of such transamidation reactions than papain or ficin (Johnston et al, 1950a;Dowmont and Fruton, 1952;Mycek and Fruton, 1957; Brubacher and Bender, 1966), whose catalytic action involves the intermediate acylation of a cysteine residue (Stockell and Smith, 1957; Lowe and Williams, 1965; Kirsch and Igelstrom, 1966). Even more effective in this regard is beef spleen dipeptidyl transferase, an oligomeric thiol enzyme (Metrione et al, 1966) which catalyzes the polymerization of dipeptide amides (or esters) with high efficiency (Jones et al, 1952;Nilsson and Fruton, 1964; Heinrich and Fruton, 1968).…”

Side-chain specificity of pepsin

“…These studies have led to the conclusion that the action of chymotrypsin is favored by the presence of an apolar side-chain B in substrates of the type ACO-NHCH(B)CO-X (where X is the leaving group), and that there is a correlation between the hydrophobic character of the B group (as measured by the partition ratio of the free amino acid between water and an organic solvent) and its effect in promoting chymotrypsin catalysis (Hymes et al, 1965;Ingles and Knowles, 1967). Other enzymes that exhibit marked preference for the presence of apolar side chains on one side of the sensitive bond, or at locations one amino acid residue away from that bond are carboxypeptidase A (Stahmann et al, 1946; Neurath and Schwert, 1950), papain (Mycek and Fruton, 1957;Schechter and Berger, 1968), streptococcal proteinase (Gerwin et al, 1966), and bacterial neutral proteinases (Morihara et al, 1968).…”

The Preparation and Properties of trans-Cinnamoyl-Papain1

“…They also have concluded that papain exhibits specificity toward the nucleophile. 44 Thus the 100-fold difference between the k4iII values for L-tryptophanamide and glycinamide reflects III).…”