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...

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...

Hydroxypyruvate reductase was purified to homogeneity from the facultative methylotroph Methylobacterium extorquens AM1. It has a molecular mass of about 71 kDa, and it consists of two identical subunits with a molecular mass of about 37 kDa. This enzyme uses both NADH (Km = 0.04 mM) and NADPH (Km = 0.06 mM) as cofactors, uses hydroxypyruvate (Km = 0.1 mM) and glyoxylate (Km = 1.5 mM) as the on...

Several modifications that have been made to the NDDO core-core interaction term and to the method of parameter optimization are described. These changes have resulted in a more complete parameter optimization, called PM6, which has, in turn, allowed 70 elements to be parameterized. The average unsigned error (AUE) between calculated and reference heats of formation for 4,492 species was 8.0 kc...

We present a combination of semiempirical quantum-mechanical (SQM) calculations in the conductor-like screening model with the MM/GBSA (molecular-mechanics with generalized Born and surface-area solvation) method for ligand-binding affinity calculations. We test three SQM Hamiltonians, AM1, RM1, and PM6, as well as hydrogen-bond corrections and two different dispersion corrections. As test case...

The conformational analysis of ethylene-norbornene chains (E-N) has been carried out using AM1, MM2, AMBER and OPLS methods taking into consideration the possibility of binding the ethylene monomers to norbornene monomers at various positions, i.e. exo-exo, exo-endo, endo-endo. The chain that is formed by connecting exo-endo positions of the monomers has lower torsional barrier energy than thos...

Theoretical studies on anthracene and a series of its derivatives were performed using the AM1 method and DFT. Based on B3LYP/6-31G(d) optimized geometries, the electronic, IR and NMR spectra of anthracene oligomers were calculated using the Indo/Cis, AM1 and B3LYP/6-31G(d) methods, respectively. The energy gaps of the oligomers decreased and the main absorptions in the electronic spectra of th...