The amino acid substitution in albumin Roma: 321 Glu----Lys.
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.
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003488:Cyanogen Bromide; D005971:Glutamates; D018698:Glutamic Acid; D006579:Heterozygote; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D008239:Lysine; D008297:Male; D009154:Mutation; D010446:Peptide Fragments / Q000302:isolation & purification; D012709:Serum Albumin / Q000235:genetics / Q000302:isolation & purification; D000075462:Serum Albumin, Human; D014357:Trypsin
D005971:Glutamates; D010446:Peptide Fragments; D012709:Serum Albumin; C056351:albumin Roma; D018698:Glutamic Acid; D014357:Trypsin; D008239:Lysine; D003488:Cyanogen Bromide; D000075462:Serum Albumin, Human