Conformational adenosine phosphates

A possible explanation for these results is shown in Fig. 11. Normally, the 2 -hydroxyl is hydrogen bonded to both His-51 and Ser-48. Note that these residues occur in the middle of a sequence that is intimately involved with defining the active site. When acyclo-NAD is bound, these residues can relocate to the position formerly occupied by the 2 -hydroxyl. The attendant movement of the protein backbone would be transmitted into the active site via Cys-46 and His-67, which are directly coordinated to the catalytic zinc, and Asp-49, which is hydrogen bonded to His-67. Arg-47, the counterion for the adenosine phosphate, and Val-57, part of the substrate binding pocket, could also participate in the structural reorganization. The sterically demanding secondary alcohols would then be more affected by conformational changes in the active site than the primary alcohols. ... 

Conformation of Guanosine and Adenosine Phosphates in Small-Molecule and Ligand/Protein Crystal Structures... 

Solvation and Shift Reagents.—The solvation parameters for a series of alcohols have been determined using the n.m.r. chemical shift of tris-n-butylphosphine oxide. Ion pair association between tetraphenylboron and cationic centres was used to study the electronic structure of aminonaphthylphosphonium salts (24 X = Ph4B ). Shift reagents have been used in the conformational analysis of adenosine phosphates and aromatic solvent induced shifts to probe the stereochemistry of butadienylphosphonates and their polymers. The geometries of difluorophosphine derivatives were evaluated from liquid crystal n.m.r. studies with the aid of electron diffraction. ... 

Calculation of Conformational Free Energies for a Model of a Bilobal Enzyme Protein kinases catalyze the transfer of phosphate from adenosine triphosphate (ATP) to protein substrates and are regulatory elements of most known pathways of signal transduction. 

Raleigh JA, Blackburn BJ (1978) Substrate conformation in 5 -AMP-utilizing enzymes 8,5 -cyclo-adenosine 5 -monophosphate. Biochem Biophys Res Commun 83 1061-1066 Raleigh JA, Fuciarelli AF (1985) Distribution of damage in irradiated 5 -AMP 8,5 -cyclo-AMP, 8-hy-droxy-AMP, and adenine release. Radiat Res 102 165-175 Raleigh JA, Whitehouse R, Kremers W (1974) Effect of oxygen and nitroaromatic cell radiosensitizers on radiation-induced phosphate release from 3 - and 5 -nucleotides A model for nucleic adds. Radiat Res 59 453-465... 

Scheme 2. Conformational changes of the y-phosphate in a) phosphoryl-transfer reaction transition state K), and various species of AlFx b) AlF41, c) A1C13. Dotted lines indicate that the degree of bond making and bond breaking determines whether the transition is more dissociative, with a metaphosphate-like intermediate, or associative, with a pentavalent intermediate. Charges have been omitted for clarity. N = adenosine or guanosine. According to [16, 17, 21]...

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