Purification and characterization of rat T-kininogens isolated from plasma of adjuvant-treated rats. Identification of three kinds of T-kininogens.

Two T-kininogens (TI- and TII-kininogens) found in plasma of Freund's adjuvant-treated rats were purified by several chromatographic procedures. The isolated TI- and TII-kininogens showed different mobilities on polyacrylamide gel electrophoresis in the absence of sodium dodecyl sulfate, but were indistinguishable in the presence of sodium dodecyl sulfate. They were also indistinguishable in amino acid composition and antigenicity, but differed in sialic acid content. The NH2- and COOH-terminal sequences were determined. In the 30 NH2-terminal residues, 2 were different. The kinin regions in the COOH-terminal portions of the two kininogens have sequences that demonstrate TI-kininogen contains a mixture of two kinin-containing regions, with substitution of 4 amino acid residues, one of which is identical to the COOH-terminal portion of alpha 1-major acute phase protein (Cole, T., Inglis, A. S., Roxburgh, C. M., Howlett, G. J., and Schreiber, G. (1985) FEBS Lett. 182, 57-61) and the other to the COOH-terminal portion of TI-kininogen (Furuto-Kato, S., Matsumoto, A., Kitamura, N., and Nakanishi, S. (1985) J. Biol. Chem. 260, 12054-12059), both predicted from cDNA sequences. The amino acid sequence of the kinin-containing region from TII-kininogen is the same as the COOH-terminal portion of TII-kininogen predicted from the cDNA. These results indicate that T-kininogens from the plasma of adjuvant-treated rats consist of a family of kininogens, that is, TI- and TII-kininogens (separable on DEAE-Sephadex A-50), and that TI-kininogen consists of at least two variants (TI alpha and TI beta) which correspond to the alpha 1-major acute phase protein reported by Cole et al. and TI-kininogen reported by Furuto-Kato et al., respectively. Immunoblotting studies with plasmas from non-inflamed and adjuvant-treated rats also indicate that T-kininogen which was previously isolated from non-inflamed rat plasma corresponds to TI-kininogen and that TII-kininogen is newly generated after treatment of rats with adjuvants.