1987 Volume 35 Issue 1 Pages 271-276
Rabbit α2-macroglobulin was isolated from rabbit plasma by polyethylene glycol precipitation, diethyl aminoethyl-Sephacel chromatography and gel chromatography. The protein subunit migrated as a single band with a molecular weight of 190000 on sodium dodecyl sulfate-gel electrophoresis under reducing conditions. Its amino-terminal amino acid sequence was determined for the first 13 residues. The amino terminus corresponded to the third residue of human α2-macroglobulin, and eleven of the 13 residues determined were identical with those of human α2-macroglobulin. These results, together with the amino acid compositions, indicate that rabbit and human α2-macroglobulins have a very similar structure. However, rabbit α2-macroglobulin was much more sensitive to methylamine inactivation than human α2-macroglobulin, and rat antisera against rabbit α2-macroglobulin did not react with human α2-macroglobulin.
