In Escherichia coli, SecA is a large, multifunctional protein that is a vital component of the general protein secretion pathway. In its membrane-bound form it functions as the motor component of the protein translocase, perhaps through successive rounds of membrane insertion and ATP hydrolysis. To understand both the energy conversion process and translocase assembly, we have used contrast-mat...

Human plasma low density lipoproteins (LDL) were deuterated in the phospholipid headgroup region by exchange with phosphatidylcholine-N(CD3)3-apolipoprotein A complexes. The exchange was associated with a net transfer of phosphatidylcholine to LDL leading to an increase in total phospholipid content by 27%. Practically all of the endogenous phosphatidylcholine including lysophosphatidylcholine,...

The scattering function and radius of gyration of an ideal polymer network are calculated depending on the strength of the bonds that form the crosslinks. Our calculations are based on an exact theorem for the characteristic function of a polydisperse phantom network that allows for treating the crosslinks between pairs of randomly selected monomers as quenched variables without resorting to re...

We perform extensive coarse-grained (CG) Langevin dynamics simulations of intrinsically disordered proteins (IDPs), which possess fluctuating conformational statistics between that for excluded volume random walks and collapsed globules. Our CG model includes repulsive steric, attractive hydrophobic, and electrostatic interactions between residues and is calibrated to a large collection of sing...

Human epidermal growth factor receptor 2 (HER2) is a member of the epidermal growth factor receptor family having tyrosine kinase activity. Overexpression of HER2 usually causes malignant transformation of cells and is responsible for the breast cancer. In this work, the virtual screening, molecular docking, quantum mechanics and molecular dynamics methods were employed to study protein–ligand ...

Light-scattering studies were done to investigate the DNA collapse transition, a large and discontinuous reduction in the radius of gyration. Of particular concern was differentiating the compaction of a single DNA molecule from aggregation. Solutions of RK2 plasmid DNA (Mr = 37 X lo6) or bacteriophage T7 DNA (Mr = 25 X lo6) were titrated with the condensing reagents spermidine in aqueous solve...

Abstract We investigate and compare the effects of two different constraints on geometrical properties linking pairs polygons simple cubic lattice, using Monte Carlo methods. One constraint is to insist that centres mass are less than distance d apart, other radius gyration pair R . The second results in links quite spherically symmetric, especially at small values , while first gives much symm...

We simulate the inversion process of a spherical micelle composed of symmetric diblock copolymers by means of dissipative particle dynamics. The evolution of micelle morphology reveals that the inversion is a two-staged process, in which a rapid agglomeration of outer lyophobic blocks occurs first, followed by a slow penetration of inner lyophilic blocks through the porous lyophobic layer. Calc...