Active Site Mimicry of Glutathione Peroxidase by Glutathione Imprinted Selenium-Containing Trypsin

نویسندگان

  • Yi Huang
  • Dan-Yang Ge
  • Hui Zong
  • Ju-Xin Yin
  • Xiao-Nan Qu
  • Shao-Wu Lv
چکیده

In order to overcome the instability of natural glutathione peroxidase (GPx), scientists endeavor to produce GPx mimics. The popular method first uses biological imprinting (BI) to produce the substrate binding sites and then employs chemical mutation (CM) to obtain the catalytic site. However, BICM has a drawback in that the catalytic site is not clear. Some researchers therefore tried to change the order of the method. These new GPx mimics were prepared by first producing the catalytic site through chemical mutation, and then employing biological imprinting to produce the substrate binding sites (CMBI). It has a clear catalytic site, but its determination of enzyme activity and kinetic analysis are still not elucidated. In this study, we used CMBI to synthesize a GPx mimic using trypsin as the imprinted molecule and GSSG as the template molecule and compared the enzyme activity of the four intermediates (Trypsin-SeO2H (TSeO2H), Trypsin-Se-SG (TSeSG), Imprinted Trypsin-Se-SG (ITSeSG), Cross-linked Imprinted Trypsin-Se-SG (CITSeSG), we analyzed the properties of intermediate products. All values are the means of at least four determinations, ITSeSG was produced from TSeSG through bio-imprinting, the activity of GPx mimics synthesized by CMBI was 5.7 times greater than native GPx, because of bio-imprinting make KmGSH value of the mimics decreased from 4.82 ± 0.27 mM (TSeSG) to 0.52 ± 0.05 mM (ITSeSG). This proves that bio-imprinting is the reason for increased substrate binding capability.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Functional mimicry of the active site of glutathione peroxidase by glutathione imprinted selenium-containing protein.

For imitating the active site of antioxidant selenoenzyme glutathione peroxidase (GPx), an artificial enzyme selenosubtilisin was employed as a scaffold for reconstructing substrate glutathione (GSH) specific binding sites by a bioimprinting strategy. GSH was first covalently linked to selenosubtilisin to form a covalent complex GSH-selenosubtilisin through a Se-S bond, then the GSH molecule wa...

متن کامل

Mechanism of Selenium - Glutathione Peroxidase and Its Inhibition by Mercaptocarboxylic Acids and

In a systematic search for effectors of glutathione peroxidase, a number of mercaptocarboxylic acids and tertiary mercaptans were found to be strong and specific inhibitors of the enzyme glutathione peroxidase. Assessment of various models was made by linear and nonlinear least squares fitting techniques. The results support the formation of reversible enzyme-inhibitor complexes. The active sit...

متن کامل

A novel selenium-containing glutathione transferase zeta1-1, the activity of which surpasses the level of some native glutathione peroxidases.

Glutathione peroxidase (GPX) is a critical antioxidant selenoenzyme in organisms that protects cells against oxidative damage by catalyzing the reduction of hydroperoxides by glutathione (GSH). Thus, some GPX mimics have been generated because of their potential therapeutic value. The generation of a semisynthetic selenoenzyme with peroxidase activity, which matches the catalytic efficiencies o...

متن کامل

Mechanism of selenium-glutathione peroxidase and its inhibition by mercaptocarboxylic acids and other mercaptans.

In a systematic search for effectors of glutathione peroxidase, a number of mercaptocarboxylic acids and tertiary mercaptans were found to be strong and specific inhibitors of the enzyme glutathione peroxidase. Assessment of various models was made by linear and nonlinear least squares fitting techniques. The results support the formation of reversible enzyme-inhibitor complexes. The active sit...

متن کامل

Microsoft Word - AHA105BF

Toshio Kaneko, MD, Third Department of Internal Medicine, Yamaguchi University School of Medicine, Koguchi, Ube Yamaguchi 755 (Japan) Oxidative damage of red cell membrane is known to be accelerated in sickle cell disease. However, the exact mechanism of this acceleration is unclear. We have read with interest the recent article entitled ‘Selenium and Glutathione Peroxidase Levels in Sickle Cel...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2017