Novel Human Butyrylcholinesterase Variants: Toward Organophosphonate Detoxication

نویسندگان

  • Mary Dwyer
  • Sacha Javor
  • Daniel A. Ryan
  • Emily M. Smith
  • Beilin Wang
  • Jun Zhang
  • John R. Cashman
چکیده

Human butyrylcholinesterase (hBChE) is currently being developed as a detoxication enzyme for stoichiometric binding and/or catalytic hydrolysis of organophosphates. Herein, we describe the use of a molecular evolution method to develop novel hBChE variants with increased resistance to stereochemically defined nerve agent model compounds of soman, sarin, and cyclosarin. Novel hBChE variants (Y332S, D340H, and Y332S/D340H) were identified with an increased resistance to nerve agent model compounds that retained robust intrinsic catalytic efficiency. Molecular dynamics simulations of these variants revealed insights into the mechanism by which these structural changes conferred nerve agent model compound resistance.

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

Identification of human butyrylcholinesterase organophosphate-resistant variants through a novel mammalian enzyme functional screen.

Human butyrylcholinesterase (hBChE) is currently being developed as a detoxication enzyme for the catalytic hydrolysis or stoichiometric binding of organophosphates (OPs). Previously, rationally designed hBChE mutants (G117H and E197Q) were reported in the literature and showed the feasibility of engineering OP hydrolytic functional activity into hBChE. However, the OP hydrolysis rate for G117H...

متن کامل

An improved cocaine hydrolase: the A328Y mutant of human butyrylcholinesterase is 4-fold more efficient.

Butyrylcholinesterase (BChE) has a major role in cocaine detoxication. The rate at which human BChE hydrolyzes cocaine is slow, with a kcat of 3.9 min(-1) and Km of 14 microM. Our goal was to improve cocaine hydrolase activity by mutating residues near the active site. The mutant A328Y had a kcat of 10.2 min(-1) and Km of 9 microM for a 4-fold improvement in catalytic efficiency (kcat/Km). Sinc...

متن کامل

In vitro detoxification of cyclosarin in human blood pre-incubated ex vivo with recombinant serum paraoxonases.

An ex vivo protocol was developed to assay the antidotal capacity of rePON1 variants to protect endogenous acetylcholinesterase and butyrylcholinesterase in human whole blood against OP nerve agents. This protocol permitted us to address the relationship between blood rePON1 concentrations, their kinetic parameters, and the level of protection conferred by rePON1 on the cholinesterases in human...

متن کامل

Cholinesterase unit establishment and issuing of >>Warning Cards<< for carriers of suxamethonium sensitive serum butyrylcholinesterase variants.

Recognition of butyrylcholinesterase (EC 3.1.1.8) variants in human serum is essential to identify patients who may be susceptible to a prolonged reaction of suxamethonium and mivacurium, short-acting muscle relaxants. Thus they can be given appropriate advice along with their relatives who may be similarly affected. Therefore, Cholinesterase Unit for detection of individuals, carriers of inher...

متن کامل

Mechanisms of organophosphate toxicity and detoxication with emphasis on studies in Croatia.

This review comprises studies on the mechanisms of toxicity and detoxication of organophosphorus (OP) compounds done in Croatia in different research areas. One area is the synthesis of antidotes against OP poisoning and their in vivo testing in experimental animals. In vitro studies included in this review focus on the mechanisms of reversible inhibition of acetylcholinesterase (AChE) and buty...

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 53  شماره 

صفحات  -

تاریخ انتشار 2014