Molecular dynamics simulation of phosphatidylcholine membrane in low ionic strengths of sodium chloride.

The one-microsecond molecular dynamics simulations of a membrane-protein complex investigate the influence of the aqueous sodium chloride solutions on the structure and dynamics of a palmitoyl-oleoyl-phosphatidylcholine bilayer membrane. The simulations were performed on five different concentrations (40, 150, 200, 300, and 400 mM) in addition to a salt-free system by using the charmm36 force field for all atoms. Four biophysical parameters, (membrane thicknesses of annular and bulk lipids, and the area per lipid of both leaflets), were computed separately.

Pre-steady-state kinetic studies of the fidelity and mechanism of polymerization catalyzed by truncated human DNA polymerase lambda.

DNA polymerase lambda (Pollambda), a member of the X-family DNA polymerases, possesses an N-terminal BRCT domain, a proline-rich domain, and a C-terminal polymerase beta-like domain (tPollambda). In this paper, we determined a minimal kinetic mechanism and the fidelity of tPollambda using pre-steady-state kinetic analysis of the incorporation of a single nucleotide into a one-nucleotide gapped DNA substrate, 21-19/41-mer (primer-primer/template). Our kinetic studies revealed an incoming nucleotide bound to the enzyme.

Membrane protein crystallization in meso: lipid type-tailoring of the cubic phase.

Hydrated monoolein forms the cubic-Pn3m mesophase that has been used for in meso crystallization of membrane proteins. The crystals have subsequently provided high-resolution structures by crystallographic means. It is possible that the hosting cubic phase created by monoolein alone, which itself is not a common membrane component, will limit the range of membrane proteins crystallizable by the in meso method.