The pairwise descreening approximation provides a rapid computational algorithm for the evaluation of solute shape effects on electrostatic contributions to solvation energies. In this article we show that solvation models based on this algorithm are useful for predicting free energies of solvation across a wide range of solute functionalities, and we present six new general parametrizations of...

The obligate methylotroph Methylophilus methylotrophus contains three distinct soluble cytochromes c. The major cytochromes, cytochrome cH (about 50% of the total) and cytochrome cL (about 42%), were similar in most respects to the cytochromes cH and cL of the facultative methylotroph Pseudomonas AM1 [O'Keeffe & Anthony (1980) Biochem. J. 192, 411-419]. Cytochrome cH had a high isoelectric poin...

The effect of different nitrogen levels on plant growth, phenol content, antioxidant and Nitrate reductase )NR) activity of cucumber (Cucumis sativus cv. Super) inoculated with mycorrhiza­ was studied. A factorial experiment based on a completely randomized design (CRD) with 6 replicates was designed. Treatments were three levels of nitrogen (NO3-50, NO3-75 and NO...

Phosphate transfer reactions are ubiquitous in nature and play fundamental roles in ATP hydrolysis and protein phosphorylation processes. The mechanisms of these reactions involve a pentacoordinated phosphorus atom that can be an intermediate or a transition state. These structures are very sensitive to both internal and external electrostatic effects and their description with quantum mechanic...

Electroporation conditions were determined for electroporating the broad-host-range plasmid pHX200V-47-ml (22.4 kb) into four pink-pigmented methylotrophic strains (Methylophilus methylotrophus AS1, Methylobacterium extorquens AM1, Methylobacterium organophilum XX, and Pseudomonas sp. M27). For these methylotrophs, a high electric-field strength (15 kV/cm) and high DNA concentration (18.75 ng/~...

A three-dimensional quantitative structure activity relationship using the eigen value analysis (EVA) paradigm applied to 41 HIV-1 integrase inhibitors that inhibit integrase mediated cleavage (3'-processing step) and integration (3'-strand transfer step) in vitro was performed. The training set consisted of 35 molecules from five structurally diverse classes: salicylhydrazines, lichen acids, c...

The collision-induced dissociation (CID) of the [Li(uracil)](+) complex with Xe is studied by means of quasi-classical trajectory calculations. The potential energy surface is obtained "on the fly" from AM1 semiempirical calculations, supplemented with two-body analytical potentials to model the intermolecular interactions. The simulations show that Li(+) production is the primary channel, in a...

conformations and electronic properties of a series of imidazobenzodiazepines are investigated by am1 semi-empirical quantum mechanics method. it is shown that substitution of cl in position 7 instead of 8, changes the geometry of the seven membered lactam ring; this may put the n5 nitrogen in a better positon to act as a hydrogen bond acceptor, and the phenyl ring in position 6 is probably mor...