The role of carbohydrate side chains of plasminogen in its activation by staphylokinase.
Kinetic parameters (k(Pg) and K(Pg)) were determined for activation of Glu-plasminogen (Glu-Pg) and Lys-plasminogen (Lys-Pg) type I (with N-linked carbohydrate chain at Asn-289) and type II (with unsubstituted Asn-289) by plasmin-staphylokinase (Pm-STA) complex. The K(Pg) values for Glu-Pg I and Lys-Pg I (17.1 and 11.2 microM, respectively) were higher than those for Glu-Pg II and Lys-Pg II (14.9 and 5.4 microM, respectively), while only minor differences in the k(Pg) values were observed between plasminogens type I and type II. Soluble fibrin significantly increased the k(Pg)/K(Pg) values for activation of all four plasminogens due to a decrease in the K(Pg) values but did not alter the k(Pg) values. However, the activation of plasminogens type I was stimulated by fibrin lesser degree than that of plasminogens type II. These findings indicate that N-glycosylation of kringle 3 of plasminogen decreases the stability of Pm-STA-Pg ternary enzyme-substrate complex in solution as well as interferes with its formation and rearrangement on the fibrin surface.
Aisina
Roza
R
Chemical Enzymology Department, Chemistry Faculty, The Lomonosov Moscow State University, 119992 Moscow, Russia. arb@enzyme.chem.msu.ru
Mukhametova
Liliya
L
Gershkovich
Karina
K
Varfolomeyev
Sergei
S
D004789:Enzyme Activation; D005337:Fibrin / Q000494:pharmacology; D005341:Fibrinolysin / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007700:Kinetics; D008666:Metalloendopeptidases / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D010958:Plasminogen / Q000737:chemistry* / Q000378:metabolism
D010446:Peptide Fragments; C018998:lysyl-plasminogen; D005337:Fibrin; D010958:Plasminogen; D005341:Fibrinolysin; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus