HspB8/Hsp22 is a functionally distinct small heat shock proteins (sHsp) and is preferentially expressed in brain, heart, skeletal, and smooth muscle. HspB8 is also associated with neuromuscular function and protein quality control by proteasomes in cardiac hypertrophy. However, the
molecular properties in vitro and molecular oligomerization remain uncertain. In this investigation, the rat HspB8 gene was expressed in E.coli cells, and mature HspB8 protein was efficiently prepared. The chaperone-like activity of HspB8 in vitro was quantitatively analyzed by model substrates.
Size exclusion chromatography revealed that HspB8 had polydisperse oligomers and underwent dynamic molecular transition in solution, existing in a dynamic equilibrium between various oligomers. In a nonphysiological solution, HspB8 was predominantly octamers. In a physiological solution (pH
7.4), HspB8 mainly formed tetramers. The dynamic interactive transition maybe was helpful to maintain its molecular complxes in solution. In a FRET assay, subunit exchange occurred frequently between the various oligomers with a rate of 0.12, 0.089, and 0.064 min-1 at 50°C, 43°C, and
37°C, respectively. It also demonstrated the dynamic molecular properties of HspB8 in solution.
Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.