G-protein coupled receptors (GPCRs) are one of the largest families of membrane receptors in eukaryotes. Heterotrimeric G-proteins, composed of α, β and γ subunits, are important molecular switches in the mediation of GPCR signaling. Receptor stimulation after the binding of a suitable ligand leads to G-protein heterotrimer activation and dissociation into the Gα subunit and Gβγ heterodimer. Th...

This paper introduces a self-consistent computational protocol for modeling protein electrostatic potentials according to static point-charge model distributions. The protocol involves a simple space-domain decomposition scheme where individual molecular domains are modeled as Quantum-Mechanical (QM) layers embedded in the otherwise classical Molecular-Mechanics (MM) protein environment. Electr...

The preferences of amino acid residues for ,psi backbone angles vary strikingly among the amino acids, as shown by the backbone angle found from the (3)J(H(alpha),H(N)) coupling constant for short peptides in water. New data for the (3)J(H(alpha),H(N)) values of blocked amino acids (dipeptides) are given here. Dipeptides exhibit the full range of coupling constants shown by longer peptides such...

abstract peroxidases are a group of oxidoreductases that are produced by a number of microorganisms and plants, and catalyse the reduction of peroxides. peroxidases are widely used in clinical biochemistry and enzyme immunoassay. horseradish peroxidase isoenzyme c (hrp) is one of the characterized peroxidases. the structure of the enzyme is largely alpha helical. kinetics studies of peroxidase ...

An understanding of the balance of chemical forces responsible for protein stability and specificity of structure is essential for the success of efforts in protein design. Specifically, electrostatic interactions between charged amino acids have been explored extensively to understand the contribution of this force to protein stability. Much research on the importance of electrostatic interact...

Implications of the DLVO theory for problems associated with colloid particle adsorption and deposition at solidrliquid interfaces were reviewed. The electrostatic interactions Ž . between two planar double-layers described by the classical Poisson]Boltzmann PB equation were first discussed. Then, the approximate models for calculating interactions of Ž . curved interfaces e.g. spheres were exp...

Two positively charged basic amino acids, arginine and lysine, are mostly exposed to protein surface, and play important roles in protein stability by forming electrostatic interactions. In particular, the guanidinium group of arginine allows interactions in three possible directions, which enables arginine to form a larger number of electrostatic interactions compared to lysine. The higher pKa...

Infection of CD4+ T cells by macrophage-tropic HIV-1 strains involves interaction of viral gp120 with the host cell chemokine receptor CCR5. The principle neutralizing determinant (PND) of the V3-loop of the HIV-1 gp120 was investigated for its interaction with CCR5 by computational modeling methods at atomic resolution and electrostatic calculations to complement experimental findings. The stu...