The long term objective of this proposal is to clarify the relationship between the molecular conformation and OSAR's of an important class of cardiovascular drugs known as calcium entry blockers or calcium channel antagonists. X-ray diffraction methods will be employed to obtain molecular conformational data for a number of these drugs. Immediate attention will be focused on a series of 1,4-dihydropyridine analogs related to the important anti-anginal drug nifedipine. Particular interest will be directed to the unsymmetric ester analogs of nifedipine which display pronounced tissue selectivity with regard to the inhibition of excitation-contraction coupling of cardiovascular tissue. Specific compounds to be investigated include nitrenedipine, which lowers elevated peripheral vascular resistance; nimodipine, which effects cerebral vasodilation without a substantial decrease in blood pressure; and nisoldipine, a potent femoral vasolilator which additionally inhibits thromboxan synthetase and protects against arachidonate-induced suddent death by preventing platelet-induced pulmonary thrombosis. The X-ray cystallographic molecular conformations of these drugs will be examined in relation to OSAR's which specify drug inhibitory potency as a function of the steric minimum width verloop parameter of the aryl ring substituents and tissue selectivity as a function of the steric and lipophilic characteristics of the ester groups. Attempts will be made to relate these concepts to the degree of dihydropyridine ring plane. Two series of six aryl ring derivatives of nimodipine and nisoldipine will be examined in this study.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL032303-03
Application #
3343662
Study Section
Biophysics and Biophysical Chemistry A Study Section (BBCA)
Project Start
1984-05-01
Project End
1987-04-30
Budget Start
1986-05-01
Budget End
1987-04-30
Support Year
3
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Hauptman-Woodward Medical Research Institute
Department
Type
DUNS #
074025479
City
Buffalo
State
NY
Country
United States
Zip Code
14203
Langs, D A (1991) The direct determination of phase invariants provided by diffraction data measured at two different temperatures. Acta Crystallogr A 47 ( Pt 5):515-21
Langs, D A; Kwon, Y W; Strong, P D et al. (1991) Molecular level model for the agonist/antagonist selectivity of the 1,4-dihydropyridine calcium channel receptor. J Comput Aided Mol Des 5:95-106
Langs, D A; Smith, G D; Courseille, C et al. (1991) Monoclinic uncomplexed double-stranded, antiparallel, left-handed beta 5.6-helix (increases decreases beta 5.6) structure of gramicidin A: alternate patterns of helical association and deformation. Proc Natl Acad Sci U S A 88:5345-9
Langs, D A; Strong, P D; Triggle, D J (1990) Receptor model for the molecular basis of tissue selectivity of 1, 4-dihydropyridine calcium channel drugs. J Comput Aided Mol Des 4:215-30
Langs, D A (1989) Structure of the ion channel peptide antibiotic gramicidin A. Biopolymers 28:259-66
Duax, W L; Langs, D A; Pangborn, W A et al. (1989) Molecular conformation and ion transport of cyclic and linear ionophores. J Mol Graph 7:82-6, 99
Triggle, D J; Langs, D A; Janis, R A (1989) Ca2+ channel ligands: structure-function relationships of the 1,4-dihydropyridines. Med Res Rev 9:123-80
Langs, D A (1988) Three-dimensional structure at 0.86 A of the uncomplexed form of the transmembrane ion channel peptide gramicidin A. Science 241:188-91
Langs, D A; Han, F (1988) Direct methods: the identification of conditions which simplify the generation of inconsistent quadrupoles. Acta Crystallogr A 44 ( Pt 5):657-61
Han, F; Langs, D A (1988) Direct methods: the identification of space-group-specific inconsistent three-phase structure invariants. Acta Crystallogr A 44 ( Pt 4):563-6

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