title: Evaluation of a new substrate for measurement of serum PON arylesterase activity.
abstract: It was found that the hydrolysis of 9-(4-chlorophenyloxycarbonyl)-10-methylacridinium triflate (CPOCMA) could be catalyzed by recombinant human PON1. Based on this property, the CPOCMA was evaluated as a substrate for serum PON activity assay. The apparent K(m) value of a serum sample for the substrate was determined as 85nmol/L, close to the K(m) value (83nmol/L) of rHuPON1. The interferences by other esterase such as acetylcholinerase and lipases were investigated. The NaCl and CaCl(2) as PON activity enhancers were able to improve the specific signal, respectively. The rHuPON1 in presence of CaCl(2) showed at least 7.8 times selectivity over acetylcholinerase and lipases. By comparing with the UV methods based on phenyl acetate and diazinon, respectively, the proposed chemiluminescent method was validated with 30 serum samples. The method based on CPOCMA allows reliable, cost-saving, and specific determination in a buffer of physiological pH.
authors.affiliation: College of Chemistry & Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing 400030, China. muxiaojingcn@yahoo.com.cn
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Mu
authors.forename: Nana
authors.initials: N
authors.lastname: Yu
authors.forename: Chengshan
authors.initials: C
authors.lastname: Wang
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zou
authors.forename: Zulipiyan
authors.initials: Z
authors.lastname: Abulimite
authors.forename: Zhining
authors.initials: Z
authors.lastname: Xia
mesh_terms: D000110:Acetylcholinesterase / Q000097:blood; D000166:Acridines / Q000737:chemistry*; D043303:Aryldialkylphosphatase / Q000097:blood*; D002021:Buffers; D002122:Calcium Chloride / Q000737:chemistry; D003976:Diazinon / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008049:Lipase / Q000097:blood; D008163:Luminescent Measurements; D010648:Phenylacetates / Q000737:chemistry; D044967:Serum; D012965:Sodium Chloride / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: C572488:9-(4-chlorophenyloxycarbonyl)-10-methylacridinium; D000166:Acridines; D002021:Buffers; D010648:Phenylacetates; D012965:Sodium Chloride; D008049:Lipase; D000110:Acetylcholinesterase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human; C025136:phenylacetic acid; D002122:Calcium Chloride; D003976:Diazinon