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...

The integral membrane protein complex between phospholamban (PLN) and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) regulates cardiac contractility. In the unphosphorylated form, PLN binds SERCA and inhibits Ca(2+) flux. Upon phosphorylation of PLN at Ser16, the inhibitory effect is reversed. Although structural details on both proteins are emerging from X-ray crystallography, cryo-electron micr...

Signaling specificity in the mitogen-activated protein kinase (MAPK) pathways is controlled by disordered domains of the MAPK kinases (MKKs) that specifically bind to their cognate MAPKs via linear docking motifs. MKK7 activates the c-Jun N-terminal kinase (JNK) pathway and is the only MKK containing three motifs within its regulatory domain. Here, we characterize the conformational behavior an...

The calculation of the entropy flexible molecules can be challenging, since number possible conformers grow exponentially with molecule size and many low-energy may thermally accessible. Different methods have been proposed to approximate contribution conformational molecular standard entropy, including performing thermochemistry calculations all stable conformations developing empirical correc...

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...

Extensive studies from different fields reveal that many macromolecules, especially enzymes, show slow transitions among different conformations. This phenomenon is named such things as dynamic disorder, heterogeneity, hysteretic or mnemonic enzymes across these different fields, and has been directly demonstrated by single molecule enzymology and NMR studies recently. We analyzed enzyme slow c...

Molecular machines order and disorder polypeptides as they form and dissolve large intermolecular interfaces, but the biological significance of coupled ordering and binding has been established in few, if any, macromolecular systems. The ordering and binding of GroES co-chaperonin mobile loops accompany an ATP-dependent conformational change in the GroEL chaperonin that promotes client protein...

The expected (E)-but-3-en-2-ones compounds I and II (half curcuminoids) were obtained by the Claisen–Schmidt reaction between aldehydes 3,4-dimethoxybenzaldehyde or 4-nitrobenzaldehyde with acetone. Concomitantly, 3-methylcyclohex-2-enones III IV arose from an unexpected of but-3-en-2-ones in cascade a Michael-type addition second molecule acetone followed Robinson annulation under strong basic...

Milk is composed of water, proteins, lipids, lactose, vit-amins, and minerals. More than 80% most mam-mals’ milk proteins are con-stituted by caseins. Casein a group they sub-divided into αs1-, αs2-, β- -casein families. Among these ca-sein families, -casein the second abundant pro-tein. Different mutations in cow gene led to 12 genetic variants common A1 A2. The A2 differ only at amino acid ...