PURIFICATION AND PARTIAL CHARACTERIZATION OF A SOLUBLE ELASTIN-LIKE PROTEIN FROM COPPER-DEFICIENT PORCINE AORTA

An elastin-like protein is present in the aortas of copper-deficient swine. This protein has been extracted with a pH 3 low-salt buffer and subjected to purification by a method of heat precipitation followed by ion-exchange chromatography. N-Terminal analysis of this protein indicated the sequence to be Gly-Gly-Val-Ile-Gly. The C-terminal amino acid is probably glycine. The molecular weight was evaluated by a sodium dodecycl sulfate disc electrophoretic system. This indi-cated the molecular size to be about 67,000 or 800 residues. The amino acid analysis of this protein is very much like that of porcine-insoluble aortic elastin except for the absence of methionine and histidine. Also, isodesmosine and dismosine are not seen and there is a lysine content of 48 residues/1000. It is suggested that this protein is the precursor of insoluble elastin and that it be referred to henceforth as tropoelastin. © 1969, American Chemical Society. All rights reserved.