Studies on factor XII in porcine plasma: purification and its conversion to activated form by porcine plasma kallikrein.
When porcine plasma was subjected to four steps of ion-exchange column chromatographies, factor XII (F. XII) was separated into two fractions, F. XII-1 and F.XII-2, and about 8.5 mg of F. XII-1 and 2.3 mg of F. XII-2 were obtained from 675 ml of the plasma. The purified proteins were found to give a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular masses of F. XII-1 and XII-2 were estimated to be about 84 kDa by SDS-PAGE, and consisted of a single polypeptide chain. However, F. XII-1 converted to active form after removing Polybrene, but F. XII-2 was not activated. Activation of F. XII-2 took place on incubation with porcine plasma kallikrein, and the activation rate was increased only in the presence of negatively charged surfaces, such as sulfatide. When the preparation was incubated with sulfatide, spontaneous activation was not observed on the condition that we used. Activation of porcine F. XII-2 by porcine plasma kallikrein was found to involve the cleavage of the peptide bond on the disulfide-bridged polypeptide chain, and further fragmentation of activated form was observed during prolonged incubation time.
Mashiko
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Division of Chemistry of Hygiene, Meiji College of Pharmacy, Tokyo Japan.
Kato
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Fujii
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Takahashi
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H
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D005172:Factor XI / Q000032:analysis; D005174:Factor XII / Q000302:isolation & purification* / Q000378:metabolism; D007610:Kallikreins / Q000378:metabolism*; D008322:Mammals / Q000097:blood; D008970:Molecular Weight; D013045:Species Specificity; D013552:Swine / Q000097:blood*
D000596:Amino Acids; D005174:Factor XII; D005172:Factor XI; D007610:Kallikreins