Two different adenylyl cyclases in brain distinguished by monoclonal antibodies

Abstract

Four monoclonal antibodies, raised against the 115‐kDa adenylyl cyclase from bovine brain [Pfeuffer, E. et al. (1985) EMBO J. 4, 3675–3679] have been selected and designated BBC‐1 to BBC‐4. BBC‐1 and BBC‐3 are highly specific for the 115‐kDa enzyme from bovine brain. The two other antibodies, BBC‐2 and BBC‐4, recognize an additional 150‐kDa adenylyl cyclase in bovine brain, but also in brain tissue from other species. In membranes from lung and myocardium (bovine and rabbit) only the 150‐kDa species is detected by the crossreacting antibodies BBC‐2 and BBC‐4.The two adenylyl cyclases from brain can be separated by calmodulin‐Sepharose: only the enzyme of 115 kDa but not that of 150 kDa was retained by the affinity resin and could be stimulated by Ca2+/calmodulin. The data obtained with these antibodies of defined specificity provide for the first time direct evidence for the presence of two distinct adenylyl cyclase species in brain tissue. Copyright © 1988, Wiley Blackwell. All rights reserved