C-terminal truncation of a bovine B12 trafficking chaperone enhances the sensitivity of the glutathione-regulated thermostability

• Published in: BMB reports 2013, 46(3), , pp.169-174
• Main Authors: Jeong, J.J., Yeungnam University, Gyeongsan, Republic of korea, Park, J.H., Yeungnam University, Gyeongsan, Republic of korea, Lee, D.Y., Yeungnam University, Gyeongsan, Republic of korea, Kim, J.H., Yeungnam University, Gyeongsan, Republic of korea
• Format: Article
• Language: English
• Subjects: B12 trafficking chaperone; GLUTATHION; GLUTATHIONE; GLUTATION; Thermostability; Thermostability,B12 trafficking chaperone; VITAMIN B12; VITAMINA B12; VITAMINE B12; 화학
• ISSN: 1976-6696; 1976-670X
• DOI: 10.5483/BMBRep.2013.46.3.158

The human B12 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 (Tm = ∼42oC) 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.