Biochemical Characterization of A Novel Thermophilic Esterase Isolated from Shewanella sp F88

The main objective of this study was to purify and characterize an esterase from Shewanella sp F88. The enzyme was purified 41-fold and an overall yield of 21 %, using a two-step procedure, including ammonium sulfate precipitation and Q-sepharore chromatography. Molecular weight of the enzyme was 62.3 kDa according to SDS-PAGE data. The enzyme showed an optimum activity at pH 6.5 and 58 ˚C. Evolution of substrate specificity demonstrated that this thermostable enzyme had the highest activity towards para-nitrophenol acetate (pNPA, C2). Michaelis-Menten constant (Km) and maximum velocity (Vmax) of pNPA-hydrolyzing reaction were 12.6 mM and 550 U.mg-1, respectively. Enzyme activity was declined in the presence of metal ions (2 and 5 mM), including Fe2+, Ca2+, Cu2+, Zn2+, Mg2+ and Mn2+. The half-lives of purified esterase was 70 and 31 min at 60 °C and 80 °C, respectively. In conclusion, the enzyme is a novel thermostable lipolytic enzyme characterized from Shewanella species

Relationship between serum anti-heat shock protein 27 antibody levels and obesity

Background Heat shock protein 27 (HSP27) is an intracellular molecular chaperone that is expressed at high levels following the exposure of cells to environmental stressors such as heat, toxins, and free radicals. High levels of HSP antigens and antibody titers have been reported in several conditions including cardiovascular disease and cancers. We measured serum anti-HSP27 antibody levels in 993 subjects and assessed the associations between serum anti-HSP27 antibody levels and demographic characteristics including coronary risk factors. Methods A total of 993 subjects were recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders (MASHAD) cohort study. Demographic, clinical, and biochemical parameters and serum anti-HSP27 antibody titers were determined in all the subjects. Results Serum anti-HSP27 antibody levels increased with increasing age in men. No significant differences in levels were detected between men and women. Serum anti-HSP27 antibody levels were significantly higher in obese subjects than in nonobese subjects (P = 0.046); however, no significant influence of smoking status was observed. Moreover, serum anti-HSP27 antibody titers were positively associated with age, body mass index, waist/hip ratio, the presence of diabetes mellitus, nonsmoking habit, serum triglycerides, cholesterol, and high-sensitivity c-reactive protein. Conclusion We have found that serum anti-HSP27 antibody titers are related to several cardiovascular risk factors, necessitating further studies on the value of this emerging marker for risk stratification