Mechanism of adenylate kinase. Dose adenosine 5'-triphosphate bind to the adenosine 5'-monophosphate site
Although the subtrate binding properties of adenylate kinase (AK) have been studied extensively by various biochemical and biophysical techniques, it remains controversial whether uncomplexed adenosine 5'-triphosphate (ATP) binds to the adenosine 5'-monophosphate (AMP) site of AK. The authors present two sets of experiments which argue against binding of ATP to the AMP site. (a) /sup 31/P nuclear magnetic resonance titration of ATP with AK indicated a 1:1 stoichiometry on the basis of changes in coupling constants and line widths. This ruled out binding of ATP to both sites. (b) ATP and MgATP were found to behave similarly by protecting AK from spontaneous inactivation while AMP showed only a small degree of protection. Such inactivation could also be protected or reversed by dithioerythritol and is most likely due to oxidation of sulfhydryl groups, one of which (cysteine-25) is located near the MgATP site. The results support binding of ATP to the MgATP site predominantly, instead of the AMP site, in the absence of Mg/sup 2 +/.
- Research Organization:
- Ohio State Univ., Columbus
- OSTI ID:
- 5400505
- Journal Information:
- Biochemistry; (United States), Vol. 26:20
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ATP
CONFIGURATION INTERACTION
NUCLEAR MAGNETIC RESONANCE
PHOSPHOTRANSFERASES
AMP
NMR SPECTRA
PHOSPHORUS 31
SUBSTRATES
ENZYMES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
RESONANCE
SPECTRA
STABLE ISOTOPES
TRANSFERASES
550601* - Medicine- Unsealed Radionuclides in Diagnostics