Preparation of antibodies to chick-embryo galactosylhydroxylysyl glucosyltransferase and their use for an immunological characterization of the enzyme of collagen synthesis

Abstract

Antibodies were prepared against chick-embryo galactosylhydroxylysyl glucosltransferase and further purified by immunoaffinity chromatography. The antibodies gave a single precipitation line of identity by double immuno-diffusion against crude or pure chick-embryo glucosyltransferase. The ability of the antibody to precipitate the transferase was not altered by destroying the secondary structure of the enzyme. The antibody also inhibited the enzyme activity. The degree of inhibition was higher with denatured citrate-soluble rat skin collagen as the substrate than with gelatinized rat skin insoluble collagen or free galactosylhydroxylysine. The cross-reactivity of the glucosyltransferase between different species was low when studied by double immunodiffusion or inhibition kinetics. The antiserum showed no detectable cross-reactivity against other intracellular enzymes of collagen biosynthesis. A line of complete identity was found in double immunodiffusion between the transferases from whole chick embryos and chick embryo tendon, kidney and cartilage. Inhibition by the antiserum of the enzyme from chick embryo tissues synthesizing different collagen types was relatively similar. The data do not support the hypothesis that galactosylhydroxylylsyl glucosyltransferase has isoenzymes with markedly different specific activities or immunological properties.