ISSN:
1042-7163
Keywords:
Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The proposed activated state of cyclic adenosine 3′,5′-monophosphate (cAMP) is modelled by two nucleoside cyclic 3 ′,5 ′ Pv-TBP compounds 3 and 4. The reason for the design of compound 3, in which a probe fragment (O—CH2—CH2—OCH3 group) is linked to phosphorus, was reflected in a conformational transmission effect, which occurs when the probe is located in the axis of a Pv-TBP. This means that the six-membered 3′5′-dioxaphosphorinane ring predominantly remains in a diequatorial (e,e) orientation. In the absence of conformational transmission, as in compound 4, the 3′,5′-dioxaphosphorinane ring favors an equatorial-axial (e,a) orientation. From this we conclude that the occurrence of conformational transmission can stabilize the (e,e) orientation of the 3′,5′-ring. This can be of relevance to the activation of protein kinase by cAMP. In order to obtain more structural information from 3 and 4, we performed MNDO calculations on the models 8-10. These calculations revealed that the (e,e) orientation of the 3′,5′-ring is destabilized by 3-4 kcal/mol compared to the (e,a) orientation. For the (e,a) geometry, the 3′,5′-ring adopts a twist conformation, whereas the (e,e) orientated 3′,5′-ring shows a half-chair geometry.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hc.520020123
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