title: Tetramer formation of a variant type human transthyretin (prealbumin) produced by Escherichia coli expression system.
abstract: A variant of human transthyretin(TTR, prealbumin) with methionine for valine substitution at position 30 is a major component of amyloid fibrils found in patients of familial amyloidotic polyneuropathy(FAP) type I, an autosomal dominant genetic disease. But the molecular nature of the variant TTR has been obscure, because most of plasma TTR from FAP patients is a mixture of variant and wild type TTR and no pure preparation of the variant has been available. For this reason, we constructed a system in which the variant type TTR was efficiently synthesized. In this system, the recombinant variant TTR was first synthesized as a fusion protein with E. coli outer membrane protein A (ompA) signal peptide, processed to eliminate the signal peptide and finally secreted to the culture medium. The final concentration of the recombinant variant TTR in the medium was about 5 mg/l. SDS polyacrylamide gel electrophoresis and gel filtration analysis suggested that the recombinant variant TTR can form tetramer as seen for native one. Purification of the protein was accomplished by only two steps of chromatography.
authors.affiliation: Research Laboratory for Genetic Information, Kyushu University, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Furuya
authors.forename: M
authors.initials: M
authors.lastname: Nakazato
authors.forename: M J
authors.initials: MJ
authors.lastname: Saraiva
authors.forename: S P
authors.initials: SP
authors.lastname: Costa
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
authors.forename: H
authors.initials: H
authors.lastname: Matsuo
authors.forename: I
authors.initials: I
authors.lastname: Goto
authors.forename: Y
authors.initials: Y
authors.lastname: Sakaki
mesh_terms: D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D010957:Plasmids; D011228:Prealbumin / Q000235:genetics* / Q000302:isolation & purification; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification
chemical_list: D011228:Prealbumin; D011994:Recombinant Proteins