Albumin Naskapi variant in North American Indians and Eti Turks.

Abstract

Both conventional polyacrylamide gel electrophoresis and a new type of electrophoretic screening procedure indicate that the polymorphic albumin variants Naskapi, found chiefly in the Naskapi Indians of Quebec, and Mersin, found in the Eti Turks of southeastern Turkey, are molecularly identical or very similar and that the amino acid substitution site in these variants is located between residues 330 and 446. This discovery is consistent with a genetic relationship between the Eti Turks and American Indians. We also report a new variant found in the Eti Turks, albumin Adana, which migrates similarly to albumin B on conventional gels but which our new system shows to differ from the common albumin A and albumin B by a substitution between residues 549 and 585.

The same substitution, glutamic acid----lysine at position 501, occurs in three alloalbumins of Asiatic origin: albumins Vancouver, Birmingham, and Adana.

“…We had received the last remaining sample of the Adana serum (<1 ml) from B. Blumberg (Philadelphia) prior to receipt of the Vancouver and Birmingham specimens. In previous work (15,16) we had confirmed the report of Franklin et al (14) that CB6 was the site of substitution in this alloalbumin, but we had not identified the amino acid exchange. In our earlier study the total albumin from the Adana serum was purified and alkylated and was divided into two aliquots.…”

“…However, investigation of human albumin variants has 'recently been stimulated by the advent of improved methods for structural study of proteins, by interest in protein genetics and 'evolution, and by knowledge ofthe complete protein (8) and genomic (9) sequence ofalbumin. As summarized by Takahashi et al (10) (14,15).…”

“…We thank the following for providing sera with albumin variants that they had studied previously: Dr. (14). This work was supported by Grant DK19221 from the National Institutes of Health.…”

Amino acid substitutions in genetic variants of human serum albumin and in sequences inferred from molecular cloning.

“…Here we report analytical studies of albumins Naskapi, Mersin, Adana, and Mexico-2, for which several genetic and epidemiological studies have been published (7,8,14,19).…”

“…Albumin Adana is a variant identified in a single Eti Turk patient of the Adana district (19). The Adana variant is a slow migrating albumin, similar to albumin B as if it had a change of an acidic to a basic amino acid; however, the CNBr fragment pattern of Adana and B differ in our isoelectric focusing system and also in the PAGE system of Franklin et al (14,19). We have localized the substitution site of albumin Adana to CB6 (residues 447-548) ( Fig.…”