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...

Semi-empirical calculations including an empirical dispersive correction are used to calculate intermolecular interaction energies and structures for a large database containing 156 biologically relevant molecules (hydrogen-bonded DNA base pairs, interstrand base pairs, stacked base pairs and amino acid base pairs) for which MP2 and CCSD(T) complete basis set (CBS) limit estimates of the intera...

A semiempirical AM1/d Hamiltonian is developed to model phosphoryl transfer reactions catalyzed by enzymes and ribozymes for use in linear-scaling calculations and combined quantum mechanical/molecular mechanical simulations. The model, designated AM1/d-PhoT, is parametrized for H, O, and P atoms to reproduce high-level density-functional results from a recently constructed database of quantum ...

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...

In this paper we propose the synthesis of 4-(anthracen-10-yl)-1-cyclohexyl-3-phenoxyazetidin2-one. In addition to its synthesis AM1 calculations to characterize the physical properties of the molecule is also presented.

The simulation of enzymatic reactions, using computer models, is becoming a powerful tool in the most fundamental challenge in biochemistry: to relate the catalytic activity of enzymes to their structure. In the present study, various computed parameters were correlated with the natural logarithm of experimental rate constants for the hydroxylation of various substrate derivatives catalysed by ...

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...