[A comparative study of alpha2-macroglobulin and pregnancy-associated alpha2-glycoprotein and protein A as possible...

Pregnancy-dependent protein A, alpha 2-glycoprotein as well as alpha 2-macroglobulin were isolated from retroplacental blood serum by means of affinity chromatography. These proteins proved to be similar in their structure, amino acid and carbohydrate compositions as well as in their properties to bind proteinases and to inhibit the enzymatic activity. The hypothesis on possible integration of these proteins into a group of high molecular inhibitors of proteinases is discussed.