SYNTHESIS OF 3′-UREIDOADENOSINE ANALOGUES AND THEIR BINDING AFFINITY TO THE A3 ADENOSINE RECEPTOR
摘要:
Novel 3'-ureidoadenosine analogues were synthesized from 1,2:5,6-di-O-isopropylidene-D-glucose in order to lead to stronger hydrogen bonding at the A(3) adenosine receptor than the corresponding 3'-aminoadenosine derivatives. However, all synthesized 3'-ureidoadenosine analogues have lost their binding affinities to the all subtypes of adenosine receptors, indicating that bulky 3'-urea moiety led to conformational distortion.
Orthogonal Activation of the Reengineered A3 Adenosine Receptor (Neoceptor) Using Tailored Nucleoside Agonists
摘要:
An alternative approach to overcome the inherent lack of specificity of conventional agonist therapy can be the reengineering of the GPCRs and their agonists. A reengineered receptor ( neoceptor) could be selectively activated by a modified agonist, but not by the endogenous agonist. Assisted by rhodopsin-based molecular modeling, we pinpointed mutations of the A(3) adenosine receptor (AR) for selective affinity enhancement following complementary modifications of adenosine. Ribose modifications examined included, at 3' : amino, aminomethyl, azido, guanidino, ureido; and at 5' : uronamido, azidodeoxy. N-6-Variations included 3-iodobenzyl, 5-chloro-2-methyloxybenzyl, and methyl. An N-6-3-iodobenzyl-3'-ureido adenosine derivative 10 activated phospholipase C in COS-7 cells (EC50 = 0.18 mu M) or phospholipase D in chick primary cardiomyocytes, both mediated by a mutant ( H272E), but not the wild-type, A(3)AR. The affinity enhancements for 10 and the corresponding 3'-acetamidomethyl analogue 6 were > 100-fold and > 20-fold, respectively. 10 concentration-dependently protected cardiomyocytes transfected with the neoceptor against hypoxia. Unlike 10, adenosine activated the wild-type A(3)AR (EC50 of 1.0 mu M), but had no effect on the H272E mutant A(3)AR (100 mu M). Compound 10 was inactive at human A(1), A(2A), and A(2B)ARs. The orthogonal pair comprising an engineered receptor and a modified agonist should be useful for elucidating signaling pathways and could be therapeutically applied to diseases following organ-targeted delivery of the neoceptor gene.
Synthesis of<i>N</i><sup>6</sup>-Substituted 3′-Ureidoadenosine Derivatives as Highly Potent Agonists at the Mutant A<sub>3</sub>Adenosine Receptor
作者:Lak Shin Jeong、Seung Ah Choe、Ae Yil Kim、Hea Ok Kim、Zhan-Guo Gao、Kenneth A. Jacobson、Moon Woo Chun、Hyung Ryong Moon
DOI:10.1080/15257770701493161
日期:2007.11.26
Several N6-substituted 3 '-ureidoadenosine derivatives were efficiently synthesized starting from D-glucose for the development of H272E mutant A3 adenosinereceptor (AR) agonists. Among compounds tested, 3 '-ureido-N6-(3-iodobenzyl)adenosine (2c) exhibited the highest binding affinity (Ki = 0.22 micro M) at the H272E mutant A3 AR without binding to the natural A3AR.