环磷腺苷, Adenosine Cyclophosphate

Adenosine 3',5'-cyclic monophosphate

Cyclic AMP (cAMP) is a central second messenger in cell signaling, propagating signals from receptors to downstream pathways. It is generated from ATP by several adenylate cyclase enzymes, which are modulated by G protein-coupled receptors. cAMP activates protein kinase A and the exchange proteins activated by cAMP (Epac1 and Epac2), which are nucleotide exchange factors for the Rap family of GTPases. cAMP is degraded to AMP by cyclic nucleotide phosphodiesterases.

Cyclic adenosine monophosphate (cAMP, cyclic AMP or 3'-5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is derived from adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway.

Cyclic AMP is a second messenger molecule comprised of an adenine ribonucleotide bearing a phosphate group bound to the oxygen molecules at the 3' and 5' positions of the sugar moiety. Cyclic AMP, which is synthesized from ATP by the intracellular enzyme adenylate cyclase, modulates the activity of several hormone-dependent signal transduction pathways.

3', 5'-Cyclic AMP, also known as cyclic AMP or camp, belongs to the class of organic compounds known as 3', 5'-cyclic purine nucleotides. These are purine nucleotides in which the oxygen atoms linked to the C3 and C5 carbon atoms of the ribose moiety are both bonded the same phosphorus atom of the phosphate group. 3', 5'-Cyclic AMP exists as a solid, slightly soluble (in water), and a moderately acidic compound (based on its pKa). 3', 5'-Cyclic AMP has been found throughout all human tissues, and has also been primarily detected in feces, urine, blood, and cerebrospinal fluid. Within the cell, 3', 5'-cyclic AMP is primarily located in the cytoplasm and golgi. 3', 5'-Cyclic AMP exists in all eukaryotes, ranging from yeast to humans. In humans, 3', 5'-cyclic AMP is involved in the dopamine activation OF neurological reward system pathway, the intracellular signalling through adenosine receptor A2B and adenosine pathway, the purine metabolism pathway, and the excitatory neural signalling through 5-HTR 4 and serotonin pathway. 3', 5'-Cyclic AMP is also involved in several metabolic disorders, some of which include the xanthinuria type I pathway, adenine phosphoribosyltransferase deficiency (aprt), molybdenum cofactor deficiency, and xanthine dehydrogenase deficiency (xanthinuria). Outside of the human body, 3', 5'-cyclic AMP can be found in a number of food items such as breadnut tree seed, fruits, european chestnut, and chinese cabbage. This makes 3', 5'-cyclic AMP a potential biomarker for the consumption of these food products.

3',5'-cyclic AMP is a 3',5'-cyclic purine nucleotide having having adenine as the nucleobase. It has a role as a human metabolite, an Escherichia coli metabolite and a mouse metabolite. It is an adenyl ribonucleotide and a 3',5'-cyclic purine nucleotide. It is a conjugate acid of a 3',5'-cyclic AMP(1-).

Title: Cyclic AMP

CAS Registry Number: 60-92-4

CAS Name: Adenosine cyclic 3’,5‘-(hydrogen phosphate)

Additional Names: adenosine3’,5‘-cyclic monophosphate; adenosine 3’,5‘-cyclic phosphate; adenosine 3’,5‘-monophosphate; adenosine 3’,5‘-phosphate; cyclic adenosine 3’,5‘-monophosphate; acrasin; 3’,5‘-AMP; cAMP

Molecular Formula: C10H12N5O6P

Molecular Weight: 329.21

Percent Composition: C 36.48%, H 3.67%, N 21.27%, O 29.16%, P 9.41%

Literature References: Key intracellular regulator of a number of cellular processes; found in most animal cells, in bacteria, and in some higher plants. First isoln and identification: Rall et al., J. Biol. Chem. 224, 463 (1957); Sutherland, Rall, ibid. 232, 1077 (1958). Molecular structure and conformation: Cook et al., J. Am. Chem. Soc. 79, 3607 (1957); Lipkin et al., ibid. 81, 6198 (1959); Watenpaugh et al., Science 159, 206 (1968). Syntheses: Smith et al., J. Am. Chem. Soc. 83, 698 (1961); Borden, Smith, J. Org. Chem. 31, 3247 (1966). Physical data: D. Lipkin et al., J. Am. Chem. Soc. 81, 6075 (1959). Functions as a mediator of hormone-action for a variety of hormones such as epinephrine, glucagon and ACTH, q.q.v. Activates phosphorylation of proteins by protein kinases. Defined as a "second messenger" because of its response to hormones ("first messengers"). Converted from adenosine triphosphate (ATP) by the enzyme adenylate cyclase. Deactivated by cyclic nucleotide phosphodiesterases which convert it to 5‘-adenylic acid. Reviews of biochemical model: Sutherland et al., J. Biol. Chem. 237, 1220-1243 (1962); Robison et al., Annu. Rev. Biochem. 37, 149 (1968); Jost, Rickenberg, ibid. 40, 741 (1971); Sutherland, J. Am. Med. Assoc. 214, 1281 (1970); Pastan, Perlman, Nature New Biol. 229, 5 (1971); G. A. Robison et al., Eds., Ann. N.Y. Acad. Sci. 185, (1971); Losert, Pharmazie 28, 351 (1973). See also Cyclic GMP. Identity with acrasin from cellular slime molds (Dictyostelium species), where it acts as a "first" rather than a "second messenger": Konijn et al., Proc. Natl. Acad. Sci. USA 58, 1152 (1967). Review of quantitative methods: Methods in Molecular Biology vol. 3, "Methods in Cyclic Nucleotide Research", Mark Chasin, Ed. (Marcel Dekker, New York, 1972). Books: G. A. Robison et al., Cyclic AMP (Academic Press, New York, 1971); Advan. Cyclic Nucleotide Res. vols. 1, 2, 3, P. Greengard, G. A. Robison, Eds. (Raven Press, New York, 1972, 1973); Handb. Exp. Pharmacol. 58, "Cyclic Nucleotides", Pt I: Biochemistry and Pt II: Physiology & Pharmacology, J. A. Nathanson, J. W. Kobabian, Eds. (Springer-Verlag, New York, 1982) 736 and 1000 pp resp.

Properties: Hydrate crystallizes from water as platelets with pearly luster, mp 219-220° (with gas evolution). [a]D -51.3° (c = 0.67). uv max (pH 2): 256 nm (e 14500); (pH 7): 258 nm (e 14650). Heat stable; resistant to inactivation by acid or alkali. Found in concns of 10-7 to 10-6 moles/kg in living cells.

Melting point: mp 219-220° (with gas evolution)

Optical Rotation: [a]D -51.3° (c = 0.67)

Absorption maximum: uv max (pH 2): 256 nm (e 14500)