Albumin Roma is an electrophoretically slow moving genetic variant of human serum albumin found in 22 unrelated families. The protein was isolated from the serum of a healthy, heterozygous subject. Analysis of CNBr fragments by isoelectric focusing allowed us to localize the mutation to fragment CNBr IV (residues 299-329). This fragment was isolated on a preparative scale by RP-HPLC and subjected to tryptic digestion. Sequential analysis of two abnormal tryptic peptides, purified by RP-HPLC, revealed that the variant arises from the substitution of glutamic acid 321 by lysine. This amino acid replacement, probably resulting from a point mutation in the structural gene, causes a change in the net charge of +2 units which is in keeping with the decreased electrophoretic mobility of the native protein.
The amino acid substitution in albumin Roma: 321 Glu----Lys.
GALLIANO, MONICA;MINCHIOTTI, LORENZO;IADAROLA, PAOLO;
1988-01-01
Abstract
Albumin Roma is an electrophoretically slow moving genetic variant of human serum albumin found in 22 unrelated families. The protein was isolated from the serum of a healthy, heterozygous subject. Analysis of CNBr fragments by isoelectric focusing allowed us to localize the mutation to fragment CNBr IV (residues 299-329). This fragment was isolated on a preparative scale by RP-HPLC and subjected to tryptic digestion. Sequential analysis of two abnormal tryptic peptides, purified by RP-HPLC, revealed that the variant arises from the substitution of glutamic acid 321 by lysine. This amino acid replacement, probably resulting from a point mutation in the structural gene, causes a change in the net charge of +2 units which is in keeping with the decreased electrophoretic mobility of the native protein.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.