Residue segregation, models

Model 1 Segregation of residue from an upwelling mantle plume... 

To test the influence of the eight TSE causing point mutations on the stability of the structured C-terminal domain of human PrP, murine PrP(121-231) was used as a model. In addition to its high strucutral similarity and 94% sequence identity to human PrP(121-231), all eight residues whose replacements segregate with inherited TSEs are identical in wild-type human and murine PrP, and the side chains that form... 

Figure 3.10 Molecular model of the amphiphilic P-peptide H-(P 3-HVal-P 3-HLys-P 3-HLeu)4-OH in an L+2 helical conformation. This axial view shows the segregation of hydrophobic and positively charged residues on opposite sides of the helix. Reproduced with permission Y. Hamuro, J.P. Schneider and W.F. DeGrado,/o ma/ of American Chemical Society, 1999,121, 12200. 1999, American Chemical Society [59]...

It is known that the UV-vis absorption of the PMDA-ODA film consists of three peaks centered at 6.4 eV (194 nm), 5.9 eV (210 nm), 4.4 eV (280 nm), and a very weak absorption tail around 3.3 eV (376 nm) [37,45,60,62,63]. LaFemina et al. [60,64], on the basis of the experimentally measured absorption spectrum, computed the electronic transition energies in PMDA-ODA using the spectroscopically parameterized CNDO/S3 model and compared with the experimental results. Fig. 20 schematically depicts the orbital charge density for HOMO and LUMO in the PMDA-ODA. It should be noted that the charge at HOMO and LUMO is localized on the ODA and PMDA residues, respectively. This means that CT can take place via the one-electron HOMO LUMO transition. Bredas and Clarke [65] earlier observed similar charge segregation behavior on the valence effective Hamiltonian non-empirical method for PMDA-ODA. Matsumoto [66,67] also confirmed this phenomenon from the INDO/S MO calculation for a large model compound, PA-ODA-PMDA-ODA-PA. 

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