Evidence for the presence of two kininogens in porcine plasma and the isolation of high-molecular-weight kininogen

Studies on porcine high molecular weight kininogen. An improved method for the purification of porcine high molecular weight kininogen and cleavage of the kininogen by the action of porcine plasma kallikrein

By introduction of stepwise DEAE Sephadex A-50 and copper-Chelating Sepharose 6B column chromatographies, about 18.5 mg of high molecular weight kininogen (HK) composed of a single polypeptide chain was obtained from 500 ml of porcine plasma. Molecular weights of reduced or non-reduced preparation were estimated to be 110 kDa and 116 kDa, respectively, by SDS-PAGE. Using the preparation, cleavage of HK by porcine plasma kallikrein (KK) was investigated. A single polypeptide HK was cleaved into two chains cross-linked by disulfide bond(s), accompanying the release of kinin. Further degradation was not observed. Molecular weights of heavy-chain (H-chain) and light-chain (L-chain) were estimated to be 61 kDa and 56 kDa, respectively, by SDS-PAGE. The amino- (N-) terminal sequences of intact HK, reduced and carboxymethylated- (RCM-) H-chain, RCM-L-chain and the peptide around the kinin moiety obtained by BrCN digestion were determined. Their sequences were highly homologous with those of bovine or human HK. These results indicate that plasma KK first cleaved the Arg-Ser bond of HK, and formed nicked HK. The second cleavage yielded bradykinin (BK) and kinin-free protein, which was apparently of equal size to the nicked HK. The structure of HK was from the N-terminus to the carboxy- (C-) terminus, H-chain-BK-L-chain.

Canine plasma kininogen: evidence for the presence of two kininogens and purification of high molecular weight kininogen and characterization as multi-functional molecule

The ratio of kininogen that is substrate of plasma kallikrein to kininogen, which is not substrate of plasma kallikrein in canine plasma, was about 1:3.6 by differential assay of kininogens. When the plasma was gel-filtered through a column of Sephacryl S-300 superfine, two fractions, which released kinin by trypsin, were obtained. These results indicate that two kininogens with different molecular weights are present in the plasma and they show different susceptibility to plasma kallikrein. One kininogen was purified by ion-exchange and zinc-chelating affinity chromatographies. Purified kininogen showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing condition and its molecular weight was 125 kDa. Released kinin from the kininogen by trypsin was bradykinin. The kininogen inhibited papain and ficin but did not inhibit bromelain at the concentration used. The kininogen bound to carboxymethylated-papain and this binding was dissociated by 3M NaSCN. Canine plasma shortened the abnormal clotting time of human high molecular weight kininogen-deficint plasma. The kininogen also shortened the abnormal clotting time of the plasma. From these results, the purified kininogen was high molecular weight kininogen and it was multi-functional protein.

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.

Factor XI: purification from porcine plasma by affinity chromatography and some properties of factor XI and activated factor XI

Porcine factor XI and activated factor XI were purified by the introduction of affinity chromatography on high molecular mass kininogen. On the affinity chromatography, it was observed that high affinity exists between porcine factor XI and high molecular mass kininogen. In the preparation, however, factor XII, plasma prekallikrein and high molecular mass kininogen were not detected. The factor XI forms a dimer, and is a heterogeneous molecule, judging from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Substrate specificity of activated factor XI and inhibition profile of activated factor XI against proteinase inhibitors were investigated by comparison with those of bovine and human activated factor XI. From these results, the properties of porcine activated factor XI show great similarities with those of bovine and human activated factor XI.

Purification of a kininogenase (kininogenase-2) from the venom of Agkistrodon caliginosus (Kankoku-Mamushi)

From the partially purified capillary permeability-increasing enzyme obtained from A. caliginosus venom, another kininogenase (kininogenase-2) was purified by gel filtration on Sephadex G-100 and ion-exchange chromatography on CM-Sephadex C-50, DEAE-Sephadex A-50, S-Sepharose Fast Flow and Q-Sepharose Fast Flow. The purified enzyme was homogeneous by polyacrylamide gel electrophoresis at pH 8.3 and SDS-gel electrophoresis. The kininogenase-2 had arginine ester hydrolytic and capillary permeability-increasing activities, and did not show any caseinolytic or clotting activity in a similar manner to a previously purified kininogenase (kininogenase-1). The purified kininogenase-2 liberated bradykinin on incubation with purified bovine high mol. wt kininogen. The rate of bradykinin release from the kininogen by kininogenase-2 was slower than that by the kininogenase-1, although both enzymes rapidly cleaved the peptide bonds in the kininogen molecule.

Purification of a kininogenase from the venom of Agkistrodon caliginosus (Kankoku-Mamushi)

During the isolation of a capillary permeability-increasing enzyme from the venom of A. caliginosus, a kininogenase was also purified from the venom by gel filtration on Sephadex G-100, ion-exchange chromatographies on CM-Sephadex C-50 and DEAE-Sephadex A-50, and gel filtration on Sephadex G-75. By this procedure, 11 mg of the purified enzyme were obtained from 4 g of the venom. The purified enzyme was homogeneous by polyacrylamide disc gel electrophoresis at pH 8.3 and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and did not show any caseinolytic or clotting activity. The purified enzyme released bradykinin from purified bovine high mol.wt kininogen. The capillary permeability was increased by injection of the purified enzyme into the depilated skin of the back of a rabbit. It is supposed that the capillary permeability-increasing activity exerted by the enzyme is due to the release of bradykinin.