title: C-terminal truncation of a bovine B(12) trafficking chaperone enhances the sensitivity of the glutathione-regulated thermostability.
abstract: The human B(12) trafficking chaperone hCblC is well conserved in mammals and non-mammalian eukaryotes. However, the C-terminal ~40 amino acids of hCblC vary significantly and are predicted to be deleted by alternative splicing of the encoding gene. In this study, we examined the thermostability of the bovine CblC truncated at the C-terminal variable region (t-bCblC) and its regulation by glutathione. t-bCblC is highly thermolabile (T(m) = ~42(o)C) similar to the full-length protein (f-bCblC). However, t-bCblC is stabilized to a greater extent than f-bCblC by binding of reduced glutathione (GSH) with increased sensitivity to GSH. In addition, binding of oxidized glutathione (GSSG) destabilizes t-bCblC to a greater extent and with increased sensitivity as compared to f-bCblC. These results indicate that t-bCblC is a more sensitive form to be regulated by glutathione than the full-length form of the protein.
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan 712-749, Korea.
authors.forename: Jinju
authors.initials: J
authors.lastname: Jeong
authors.forename: Jihyun
authors.initials: J
authors.lastname: Park
authors.forename: Dong-Yeon
authors.initials: DY
authors.lastname: Lee
authors.forename: Jihoe
authors.initials: J
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D005978:Glutathione / Q000378:metabolism*; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D014805:Vitamin B 12 / Q000378:metabolism*
chemical_list: D018832:Molecular Chaperones; D005978:Glutathione; D014805:Vitamin B 12