UnissResearch

Logo Universitàegli studi di Sassari
titoli, abstracts, parole chiave >>>
A Genetic variant of albumin (albumin Asola; Tyr140->Cys) with no free-SH group but with an additional disulfide bridge

Minchiotti, Lorenzo and Galliano, Monica and Kragh-Hansen, Ulrich and Watkins, Scott and Madison, Jeanne and Putnam, Frank (1995) A Genetic variant of albumin (albumin Asola; Tyr140->Cys) with no free-SH group but with an additional disulfide bridge. European Journal of Biochemistry, Vol. 228 (1), p. 155-159. eISSN 1432-1033. Article.

Full text not available from this repository.

DOI: 10.1111/j.1432-1033.1995.0155o.x

Abstract

A slow migrating variant of human serum albumin, present in lower amount than the normal protein, has been detected by routine clinical electrophoresis at pH 8.6 in two members of a family living in Asola (Lombardia, Italy). Ion-exchange chromatography of serum samples failed to separate the normal protein from the variant. Analysis of the albumin peak by SDS/PAGE revealed that the variant had a lower apparent molecular mass than its normal counterpart. However, the abnormal band was not detectable when the separation was performed under reducing conditions or when both albumins were carboxymeth-ylated. Isoelectric-focusing analysis of CNBr fragments localized the mutation to fragment CNBr 3 (residues 124–298). This fragment was isolated on a preparative scale and subjected to tryptic digestion. Sequence determination of the abnormal tryptic peptide revealed that the variant arises from a Tyr140→Cys substitution. This result was confirmed by DNA sequence analysis, which showed a single transition of TAT→TGT at nucleotide position 5074. Despite the presence of an additional cysteine residue, several lines of evidence indicated that albumin Asola has no free-SH group; therefore, we propose the formation of a new S-S bond between Cys140 and Cys34, the only free sulphydryl group present in the normal protein. The relatively low level of the variant in serum and its abnormal mobility on cellulose acetate electrophoresis and SDS/PAGE are probably caused by a gross conformational change of the molecule induced by the new S-S bridge.

Item Type:Article
ID Code:1279
Status:Published
Refereed:Yes
Uncontrolled Keywords:Human serum albumin, genetic variant, amino acid sequence, DNA sequence, point mutation
Subjects:Area 05 - Scienze biologiche > BIO/10 Biochimica
Divisions:001 Università di Sassari > 01 Dipartimenti > Scienze biomediche
Publisher:Blackwell Science on behalf of the Federation of European Biochemical Societies / Wiley
eISSN:1432-1033
Copyright Holders:© FEBS 1995
Deposited On:18 Aug 2009 10:04

I documenti depositati in UnissResearch sono protetti dalle leggi che regolano il diritto d'autore

Repository Staff Only: item control page