NBO analysis, hybrid density functional theory (B3LYP/6-311+G**) and ab initio molecular orbital (HF/6-311+G**) based methods were used to study the anomeric effects (AE), electrostatic interactions, dipole-dipole interactions and steric repulsion effects on the conformational properties of 2-methoxy- (1), 2-methylthio- (2), 2-methylseleno- (3), 2-fluoro- (4), 2-chloro- (5) and 2-bromocyclohexa...

MOTIVATION Current methods for identifying sequence specific binding sites in DNA sequence using position specific weight matrices are limited in both sensitivity and specificity. Double strand DNA helix exhibits sequence dependent variations in conformation. Interactions between macromolecules result from complementarity of the two tertiary structures. We hypothesize that this conformational v...

Proteins are complex systems made up of many conformational sub-states which are mainly determined by the folded structure. External factors such as solvent type, temperature, pH and ionic strength play a very important role in the conformations sampled by proteins. Here we study the conformational multiplicity of calmodulin (CaM) which is a protein that plays an important role in calcium signa...

cystic fibrosis (cf) is the most common inherited disorder in caucasian populations, with over 1400 cystic fibrosis transmembrane conductance regulator (cftr) mutations. the type of mutations and their distributions varies widely between different countries and/or ethnic groups. seventy iranian cystic fibrosis patients were screened for the cftr gene mutation using arms/pcr (amplification refra...

ab initio calculations at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the importantenergy-minimum conformations and transition-state geometries of 1, 3-diazacyclohepta-1, 2-diene (2) and 1, 3-diazacycloocta-1, 2-diene (3). the c2 symmetric twist-chair (2-tc)conformation of 2 is calculated to be 7.4 kj...

ab initio calculation at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the important energyminimumconformations and transition-state geometries of of cyclodeca-1,2,3-triene (1). the mostfavorable conformation of 1 is a unsymmetrical twist-chair (1-tc) structure. degenerateinterconversion of 1-tc with it...

the effects of electromagnetic fields (emfs) radiation at the frequency of 940 mhz on the structure and function of human adult and fetal hemoglobin (hba and hbf) were studied. after extraction and purification of hba and hbf, the oxygen absorption values for exposed and unexposed hba and hbf to emf were compared. the slope of oxygen absorption curve for exposed hba was increased while that for...

thermal conformational changes in human serum albumin (hsa) in present with a 10 mm phosphate buffer, at ph=7 have been investigated via circular dichroism (cd) and uv spectroscopic methods. the results indicate that temperature in a range of 25oc to 55oc could induce a reversible conformational change in the structure of hsa. the hsa phase transition corresponds to the physiological and pathol...