Vibrio vulnificus secretes a broad-specificity metalloprotease capable of interfering with blood homeostasis through prothrombin activation and fibrinolysis.
Vibrio vulnificus is a causative agent of serious food-borne diseases in humans related to the consumption of raw seafood. It secretes a metalloprotease that is associated with skin lesions and serious hemorrhagic complications. In this study, we purified and characterized an extracellular metalloprotease (designated as vEP) having prothrombin activation and fibrinolytic activities from V. vulnificus ATCC 29307. vEP could cleave various blood clotting-associated proteins such as prothrombin, plasminogen, fibrinogen, and factor Xa, and the cleavage could be stimulated by addition of 1 mM Mn2+ in the reaction. The cleavage of prothrombin produced active thrombin capable of converting fibrinogen to fibrin. The formation of active thrombin appeared to be transient, with further cleavage resulting in a loss of activity. The cleavage of plasminogen, however, did not produce an active plasmin. vEP could cleave all three major chains of fibrinogen without forming a clot. It could cleave fibrin polymer formed by thrombin as well as the cross-linked fibrin formed by factor XIIIa. In addition, vEP could also cleave plasma proteins such as bovine serum albumin and gamma globulin, and its broad specificity is reflected in the cleavage sites, which include Asp207-Phe208 and Thr272-Ala273 bonds in prothrombin and a Tyr80-Leu81 bond in plasminogen. Taken together, the data suggest that vEP is a broad-specificity protease that could function as a prothrombin activator and a fibrinolytic enzyme to interfere with blood homeostasis as part of the mechanism associated with the pathogenicity of V. vulnificus in humans and thereby facilitate the development of systemic infection.
Chang
Alan K
AK
Research Center for Proteineous Materials, Chosun University, 375 Seosuk-dong, Dong-gu, Gwangju 501-759, Republic of Korea.
Kim
Hyo Young
HY
Park
Jung Eun
JE
Acharya
Pankaj
P
Park
Il-Seon
IS
Yoon
Seong Myeong
SM
You
Ho Jin
HJ
Hahm
Kyung-Soo
KS
Park
Jong Kun
JK
Lee
Jung Sup
JS
D002412:Cations / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D026122:Factor XIIIa / Q000378:metabolism; D005342:Fibrinolysis / Q000502:physiology*; D006706:Homeostasis; D006801:Humans; D066298:In Vitro Techniques; D045726:Metalloproteases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D010958:Plasminogen / Q000378:metabolism; D011516:Prothrombin / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013379:Substrate Specificity; D014735:Vibrio Infections / Q000382:microbiology*; D041261:Vibrio vulnificus / Q000201:enzymology*; D005719:gamma-Globulins / Q000378:metabolism
D002412:Cations; D004791:Enzyme Inhibitors; D005719:gamma-Globulins; D012710:Serum Albumin, Bovine; D011516:Prothrombin; D010958:Plasminogen; D026122:Factor XIIIa; D045726:Metalloproteases