the channel-forming antibiotic alamethicin activated rat lung particulate guanylate cyclase ( gtp pyrophosphate-lyase ( cyclizing ) ec 4.6.1.2 ) , and the activated enzyme was further stimulated by sodium nitroprusside when a thiol such as 2-mercaptoethanol was present .
C0018358
guanylate cyclase
C0024188
lyase