Enzymatic resynthesis of the "reactive site" bond in the modified aprotinin derivatives [seco-15/16]aprotinin and [Di-seco-15/16,39/40]aprotinin.
On incubation of [di-seco-15/16,39/40]aprotinin with human plasmin, porcine pancreatic kallikrein or bovine or porcine trypsin in neutral or slightly alkaline solutions [seco-39/40]aprotinin is slowly formed with enzymatic resynthesis of the reactive-site bond 15/16. With chymotrypsin, however, further degradation of [di-seco-15/16,39/40]aprotinin takes place without enzymatic resynthesis. The apparent rate constants for the synthesis of [seco-39/40]aprotinin with kallikrein and trypsin have been determined and indicate that the bond-forming reaction is 10-200-fold slower with [di-seco-15/16,39/40]aprotinin than with [seco-15/16]aprotinin. The newly formed [seco-39/40]aprotinin has similar kinetic constants for the complexation with its cognate enzymes as aprotinin, indicating that any distortion of the secondary binding region due to cleavage of the Arg39-Ala40 bond does not seriously influence binding and affinities.
Schnabel
E
E
BAYER AG, Geschäftsbereich Pharma EP-FE, Institut für Biochemie.
Reinhardt
G
G
Schröder
W
W
Tschesche
H
H
Wenzel
H R
HR
Mehlich
A
A
D000818:Animals; D007611:Aprotinin / Q000378:metabolism*; D001665:Binding Sites; D002417:Cattle; D002918:Chymotrypsin / Q000378:metabolism; D005341:Fibrinolysin / Q000378:metabolism*; D006801:Humans; D007610:Kallikreins / Q000378:metabolism*; D007700:Kinetics; D010179:Pancreas / Q000201:enzymology; D013552:Swine; D014357:Trypsin / Q000378:metabolism*
D007611:Aprotinin; D007610:Kallikreins; D002918:Chymotrypsin; D014357:Trypsin; D005341:Fibrinolysin