The extraction and partial characterization of proteins released by decalcification from calcified human aortic...

Tissue from severely atherosclerotic human aortas was divided into heavily calcified (plaque) and less calcified (non-plaque) areas. After defatting and thorough extraction with neutral salt solutions, further proteinaceous material was released from plaque than non-plaque areas. Although organic phosphorous was associated with the EDTA-solubilized protein from both plaque and non-plaque areas, the phosphorous to protein ratio of extracts from plaque areas was 2 to 3 times that from non-plaque areas. Analysis of the major protein component of the extract of plaque areas indicated an acidic glyco-protein which appeared to be associated with an organic phosphorous moiety as well as cholesterol and cholesterol esters.