Molecular modeling investigations

Rate constants for reaction of cis-[Pt(NH3)2(H20)Cl]+ with phosphate and with S - and 5/ -nucleotide bases are 4.6xl0-3, 0.48, and 0.16 M-1s-1, respectively, with ring closure rate constants of 0.17 x 10 5 and 2.55x10-5s-1 for subsequent reaction in the latter two cases 220). Kinetic aspects of interactions between DNA and platinum(II) complexes such as [Pt(NH3)3(H20)]2+, ds-[Pt(NH3)2(H20)2]2+, and cis-[Pt(NH3)2(H20)Cl]+, of loss of chloride from Pt-DNA-Cl adducts, and of chelate ring formation of cis-[Pt(NH3)2(H20)(oligonucleotide)]"+ intermediates implicate cis-[Pt(NH3)2(H20)2]2+ rather than cis-[Pt(NH3)2 (H20)C1]+, as usually proposed, as the most important Pt-binder 222). The role of aquation in the overall scheme of platinum(II)/DNA interactions has been reviewed 223), and platinum(II)-nucleotide-DNA interactions have been the subject of molecular modeling investigations 178). 

Various endeavors have been undertaken to get insight into the 3D selector-selectand complex structures and to elucidate chiral recognition mechanisms of cinchonan carbamate selectors for a few model selectands (in particular, DNB-Leu). Such studies comprised NMR [92-94], ET-IR [94-96], X-ray diffraction [33,59,92,94], and molecular modeling investigations (the latter focusing on molecular dynamics [92,93,97], and 3D-QSAR CoMFA studies [98]). 

The crucial role of the bulky substituent at Cl in (, )-l in maintaining the rigidity of the intermediate species is supported by a molecular modeling investigation and it has also been shown experimentally that whereas the introduction of a phenyl group at Cl is sufficient to produce a highly enantioselective catalyst, the introduction of an H atom or a Me group results in deactivation of the catalyst [8 i, 37]. 

Haselhorst, T., Blanchard, H., Frank, M., et al. (2007). STD NMR spectroscopy and molecular modeling investigation of the binding of A-acetylneuraminic acid derivatives to rhesus rotavirus VP8 core. Glycobiology, 1, 68-81. 

T. Haselhorst, J. C. Wilson, A. Liakatos, M. J. Kiefel, J. C. Dyason, and M. von Itzstein, NMR spectroscopic and molecular modeling investigations of the trans-siahdase from Trypanosoma cruzi, Glycobiology, 14 (2004) 895-907. 

Hofmann, D., Enhialgo-Castano, M., Lebret, A., Heuchel, M., and Yampolsldi, Y., Molecular modeling investigation of free volume distributions in stiff chain polymers with conventional and ultrahigh free volume comparison between molecular modeling and positron lifetime studies. Macromolecules, 36, 8528-8538 (2003). 

Denny BJ, Wheelhouse RT, Stevens MFG et al. NMR and molecular modeling investigation of the mechanism of activation of the antitumour drug temozolomide and its interaction with DNA. Biochemistry 1994 33 9045-9051. 

Maconi, A. et al. (2002) Synthesis, biological properties, and molecular modeling investigation of the first potent, selective, and water-soluble human A(3) adenosine receptor antagonist. Journal of Medicinal Chemistry, 45, 3579—3582. 

Braccini I., Grasso R.P., Perez S., Conformational and configurational features of acidic polysaccharides and their interactions with calcium ions A molecular modelling investigation, Carhohydr. Res., 317,1999, 119-130. 

Hofmaim, D., et al.. Molecular Modeling Investigation of Free Volume Distributions in Stiff Chain Polymers with Conventional and Ultrahigh Free Volume Comparison Between Molecular Modeling and Positron Lifetime Studies. Macromolecules, 2003, 36(22), 8528-8538. 

---