Adenosine monophosphate
Adenosine monophosphate, also known as
AMP, is the product of
adenosine condensation with a single
phosphate group:
AMP can be produced during ATP synthesis by the enzyme adenylate kinase by combining two ADP molecules:
- 2 ADP → ATP + AMP
Or AMP may be produced by the hydrolysis of one
high energy phosphate bond of ADP:
- ADP → AMP + Pi
AMP can also be formed by hydrolysis of
ATP into AMP and
pyrophosphate:
- ATP → AMP + PPi
When
RNA is broken down by living systems,
nucleoside monophosphates, including adenosine monophosphate, are formed.
AMP can be regenerated to ATP as follows:
- AMP + ATP → 2 ADP (adenylate kinase in the opposite direction)
- 2 ADP + 2 Pi → 2 ATP (this step is most often performed in aerobes by the ATP synthase during oxidative phosphorylation)
AMP can be converted into IMP by the
enzyme myoadenylate deaminase, freeing an
ammonia group.
In a catabolic pathway, adenosine monophosphate can be converted to uric acid, which is excreted from the body.
cAMP
AMP can also exist as a cyclic structure known as cyclic AMP (or cAMP). Within certain cells the enzyme adenylate cyclase makes cAMP from ATP, and typically this reaction is regulated by hormones such as adrenaline or glucagon. cAMP plays an important role in intracellular signalling.