title: Cysteine conjugate beta-lyase of rat kidney cytosol: characterization, immunocytochemical localization, and correlation with hexachlorobutadiene nephrotoxicity.
abstract: Cysteine conjugate beta-lyase (beta-lyase) was purified to electrophoretic homogeneity from the kidney cytosol of male Wistar rats. The highly purified enzyme exhibited a monomeric molecular weight of 50,000 Da and was active in the alpha-beta elimination of cysteine conjugates including S-(1,2-dichlorovinyl)-L-cysteine (DCVC), S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFEC), and S-(2-benzothiazolyl)-L-cysteine, particularly toward DCVC and TFEC. The purified enzyme also exhibited glutamine transaminase K activity with phenylalanine and alpha-keto-gamma-methiolbutyrate as substrates. An antibody was raised to the purified rat protein in sheep and the crude immune serum affinity purified, yielding a specific antibody that recognized only the beta-lyase protein in whole kidney homogenates. Immunocytochemical studies on rat kidney sections stained with the purified antibody revealed that the cytosolic beta-lyase enzyme was mainly localized in the pars recta of the proximal tubule in untreated rats. This localization is coincident with the site-specific kidney necrosis produced by hexachloro-1,3-butadiene (HCBD). These results indicate that the tissue localization of beta-lyase in the proximal tubule plays an important role in determining the specific nephrotoxicity produced by halogenated alkenes such as HCBD.
authors.affiliation: University of Surrey, Biochemistry Department, Guildford, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: MacFarlane
authors.forename: J R
authors.initials: JR
authors.lastname: Foster
authors.forename: G G
authors.initials: GG
authors.lastname: Gibson
authors.forename: L J
authors.initials: LJ
authors.lastname: King
authors.forename: E A
authors.initials: EA
authors.lastname: Lock
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002070:Butadienes / Q000378:metabolism / Q000633:toxicity*; D003429:Cross Reactions; D003600:Cytosol / Q000201:enzymology; D007150:Immunohistochemistry; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D008190:Lyases / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D000637:Transaminases / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification
chemical_list: D002070:Butadienes; C001335:hexachlorobutadiene; D000637:Transaminases; C427605:glutamine - phenylpyruvate transaminase; C021481:kynurenine-oxoglutarate transaminase; D008190:Lyases