[Effect of synthetic cationic peptides on activation of the adenylyl cyclase signaling system by biogenic amines in muscle tissue of molluscs and rats].
The hormone-sensitive adenylyl cyclase signaling system (ACS), made of serpentine receptor, heterotrimeric G-protein and enzyme adenylyl cyclase (AC), regulates a wide spectrum of growth and metabolic processes in the cell. Molecular mechanisms of functional coupling of ACS components still remain obscure. We examined the influence of synthetic cationic peptides Ac-Ala-His(Ala)2-His-Ala-NH2 (I), Ac-Ala-His-(Ala)3-His-(Ala)2-His-Ala-NH2 (II), and Ac-(Pro)2-His-(Ala)2-His-(Ala)3-His-(Ala)2-His-Ala-NH2 (III) on the basal AC activity and that stimulated by nonhormonal (NaF) and hormonal reagents (serotonin--molluscs, beta-isoproterenol--rats) in smooth muscles of the freshwater bivalve molluscs Anodonta cygnea and in skeletal muscles of rats. Peptides II and III (the latter more effective) were shown to decrease hormone-stimulated AC activity in both tissues, in a dose-dependent manner. Peptide III strongly reduced NaF stimulating effect to AC, which suggests the involvement of this peptide in the functional coupling of both receptors with G-proteins, and of G-proteins with AC. A correlation was found between the efficacy of peptide action on the functional activity of ACS components and peptide length. As shown by IR-spectroscopy, in water all peptides can form helical structures. However, alpha-helicity of peptides I and II was higher than that of peptide III, which does not conform to a power series in efficacy of these peptides. Thus, it is the length of cationic peptides that plays a key role in hormonal regulation of the functional activity of ACS, especially on the step of receptor-G-protein coupling.
Shpakov
A O
AO
Institute of Macromolecular Compounds RAS, St. Petersburg.
Korol'kov
V I
VI
Vlasova
E N
EN
Afonina
M P
MP
Vlasov
G P
GP
D000262:Adenylyl Cyclases / Q000502:physiology*; D000818:Animals; D001679:Biogenic Amines / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000502:physiology; D008974:Mollusca; D018482:Muscle, Skeletal / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D011985:Receptors, Serotonin / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects*
D001679:Biogenic Amines; D010455:Peptides; D011985:Receptors, Serotonin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases
Vliianie sinteticheskikh kationnykh peptidov na aktivatsiiu adenilattsiklaznoĭ signal'noĭ sistemy biogennymi aminami v myshechnykh tkaniakh molliuskov i krys.