Purification and characterization of two isoforms of T-kininogens from rat liver microsomes.
T-Kininogen is one of the acute phase proteins, and is a precursor of T-kinin and a cysteine protease inhibitor. Two homologous T-kininogens (TI- and TII-kininogens) were isolated from microsomal fraction of inflamed rat liver, by chromatographies on columns of DEAE-Sepharose CL-6B and DEAE-5PW and by affinity chromatography on a column of anti T-kininogen monoclonal antibody. The amino terminal amino acid sequences of the two microsomal pyridylethylated T-kininogens after pyroglutamyl aminopeptidase treatment were identical with those of TI- and TII-kininogens from inflamed rat plasma. Microsomal T-kininogens moved faster on SDS-PAGE after treatment with endoglycosidase H. The amounts of microsomal TI- and TII-kininogens in inflamed and non-inflamed rat liver were quantitated by immunoblotting of homogenates of liver microsomes using anti T-kininogen rabbit antiserum. The amounts of microsomal T-kininogens were increased in inflamed rat liver, but the ratio of the amounts of TI-kininogen to TII-kininogen was not different in the inflamed and non-inflamed rat liver. On the other hand, TII-kininogen was not significantly detected in non-inflamed rat plasma. These results indicate that the secretion of one of the T-kininogens, TII-kininogen, into plasma may be prevented by some unknown mechanism.
Enjyoji
K
K
National Cardiovascular Center Research Institute, Osaka.
Kato
H
H
D000595:Amino Acid Sequence; D000818:Animals; D002847:Chromatography, Agarose; D006520:Hepatitis, Animal / Q000378:metabolism; D007704:Kininogens / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification*; D008862:Microsomes, Liver / Q000737:chemistry*; D008969:Molecular Sequence Data; D051381:Rats; D011919:Rats, Inbred Strains
D007704:Kininogens