Polymorphism in purified guanylate cyclase from vertebrate rod photoreceptors.
Guanylate cyclase from rod photoreceptors of amphibian (toad, Bufo marinus, and frog, Rana catesbeiana) and bovine retinas was solubilized and purified by a single chromatography step on a GTP-agarose column. Silver staining of purified amphibian enzymes in SDS/polyacrylamide gels disclosed a doublet band (110 and 115 kDa), while the bovine enzyme appeared as a singlet band (110 kDa). The identification of these guanylate cyclases was confirmed using three chromatography systems with the purified enzymes. Specific binding to Con A-Sepharose suggested that rod guanylate cyclase is a glycoprotein. Two-dimensional gel electrophoresis of purified toad, frog, and bovine enzymes resolved two, three, and five variants, respectively, that differed in isoelectric point. Two variants of toad guanylate cyclase showed differences in various characterizations. These data suggest multiple mechanisms for regulation of guanylate cyclase activity in vertebrate rod photoreceptors.
Cellular and Molecular Biology Group, Los Alamos National Laboratory, University of California, NM 87545.
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Hayashi
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Yamazaki
D000818:Animals; D002024:Bufo marinus; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D002846:Chromatography, Affinity / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D003902:Detergents; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D006162:Guanylate Cyclase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D011110:Polymorphism, Genetic; D011892:Rana catesbeiana; D012374:Rod Cell Outer Segment / Q000201:enzymology*; D012995:Solubility; D014714:Vertebrates
D003902:Detergents; D006162:Guanylate Cyclase