Title
Role of C‐Terminal Tail Region of Human MtnB Enzyme for Its Tetramer Stability
Author
Hee Jung Ha, Ji Young Lee, Wonchull Kang, Jin Kuk Yang
Year
2015
Journal
Bulletin of the Korean Chemical Society
Abstract
MtnB-ΔC behaved as tetramer just like MtnBWT in the usual biochemical buffer condition used for the SEC analysis. However, their difference in the tetramer stability was demonstrated under moderately chaeotropic conditions used for the SDS-PAGE experiments in this study. In addition, the difference in the tetramer stability was corroborated by the thermal denaturation analysis. Altogether, these results suggest that the C-terminal region of MtnB though not detrimental for maintaining the tetramer assembly, contributes to the stability of the tetramer to a significant level. Considering the general principle on the cooperativity of oligomeric enzymes and, more importantly, the fact that the active site of MtnB is formed in the inter-subunit interface as revealed from its crystal structure,4 its tetramer stability must consequently affect the biochemical features not only in in vitro setting as shown in this study but also in cellular circumstances. Notably, we found that the C-terminal tail region is present only in eukaryote MtnBs but absent in prokaryote orthologues (Figure 4 in Kang et al., 2014).4 Evolutionary development of the Cterminal tail region in MtnB may indicate its beneficial effects including its contribution to tetramer assembly.
Instrument
J-1500
Keywords
Circular dichroism, Secondary structure, Thermal stability, Thermodynamics, Biochemistry