title: A proof-of-concept receptor-based assay for sulfonamides.
abstract: The gene encoding the dihydropteroate synthase (DHPS) of Streptococcus pneumonia has been cloned, sequenced, and expressed in Escherichia coli. The protein has been purified and used to develop a novel microplate assay for the detection of sulfonamides. The assay was based on the competition between sulfonamides and horseradish peroxidase (HRP)-labeled sulfonamide derivative, 4-(4-aminobenzenesulfonylamino) benzoic acid (CS) for the immobilized protein. Under optimized conditions, nine sulfonamides and p-aminobenzoic acid (PABA) could be detected below 100 ng/ml and 28 sulfonamides used in the study could be detected with IC50 values ranging from 426 to 50,000 ng/ml. It is concluded that this method offers a robust and rapid alternative to other methods for the screening of sulfonamides.
authors.affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liang
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Wen
authors.forename: Tiejun
authors.initials: T
authors.lastname: Mi
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Suxia
authors.initials: S
authors.lastname: Zhang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001681:Biological Assay / Q000379:methods*; D003001:Cloning, Molecular; D004094:Dihydropteroate Synthase / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D011485:Protein Binding; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000201:enzymology; D013449:Sulfonamides / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D013449:Sulfonamides; D004094:Dihydropteroate Synthase