Conformational analysis poly

From the conformational analysis poly(MDI-BDO) is seen to be fully extended, with an all-trans butandiol unit. Thus it must be concluded that the poly(MDI-PDO) and poly(MDI-EDO) conformations are contracted and that there are some gauche conformations in the 0-(CH2)x-0 sections of the chains. 

Allen RW and Allcock HR. Conformational analysis of poly(alkoxy- and aryloxyphosphazene) [J]. Macromolecules, 1976, 9(6), 956-961. 

PI Miyazawa, T., In Poly-Alpha-Amino Acids Proteins Models for Conformational Analysis, Fasman, G. D., Ed. Marcel Dekker New York, (1967) p 69. 

N 017 "Conformational Analysis of Macromolecules. IV. Helical Structures of PolyfL-alanine), Poly(L-valine), Poly(p-methyl-L-aspartate), Polyly-methyl-l.-glutamate),... 

The conformational analysis, according to Brewster, of isotactic poly-a-olefins demonstrates that, in the case of poly-(S)-3-methyl-1-pentene and poly-(S)-4-methyl-l-hexene, only 3 conformations are allowed for each monomeric unit two of them correspond to a left-handed helix conformation of the principal chain and one to a right-handed helix conformation (Table 25). 

Several work are concerned with the synthesis, characterization, dielectric behavior and conformational analysis of dendronized Polymers. Poly(methacrylates) containing phtalimidoalkyl moieties in the side chain have been recently studied i.e. poly(3,5-diphtalimido alkylphenyl methacrylate)s with ethyl (P-EthylGi), propyl (P-PropylGi) and butyl (P-ButylGi) chains as spacer groups. Where Gi indicates first generation [112],... 

Matsuura H, Fukuhara K (1985) Conformational-analysis of poly(oxyethylene) chain in aqueous-solution as a hydrophilic moiety of non-ionic surfactants. J Mol Struct 126 251-260... 

R. A. Scott and H. A. Scheraga, J. Chem. Phys., 45, 2091 (1966). Conformational Analysis of Macromolecuies. 111. Helical Structures of Polyglycine and Poly-L-alanine. 

D. R. Ripoll and H. A. Scheraga, Biopolymers, 27, 1283 (1988). On the Multiple-Minima Problem in the Conformational Analysis of Polypeptides. II. An Electrostatically Driven Monte Carlo Method—Tests on Poly(l-Alanine). 

In summary, we have therefore seen that poly-L-lysine presents a valuable model for a partially helical polypeptide chain, one which is amenable to conformational analysis by optical rotatory dispersion. The method by which residues in a helical conformation may be discerned and counted against a background of disordered regions has been illustrated with this polypeptide under almost ideal conditions. The adequacy of the method is corroborated by copolymers a step closer to proteins in complexity, but some of the limitations that will be encountered in its application to proteins are already foreshadowed. Before this application is discussed, however, two other phenomena relevant to protein structure that are clearly exhibited in synthetic polypeptides, the helix-coil transition and the /3-conformation, will be considered. 

The aim of this final section is twofold. It will first examine the basis upon which the rotatory dispersions of proteins may be treated in the same manner that has been employed for synthetic polypeptides and, secondly, assess the extent to which the dispersive properties of proteins may be quantitatively explained in terms of known conformations of a polypeptide chain. A pattern of conformational analysis embodying the hypothesis that a polypeptide chain is partitioned into standard helical segments and disordered regions has been shown capable of a rather precise estimate of partial helical content in polymers such as poly-L-lysine and copoly-L-... 

Exciton couplet was also observed in the Ba absorption band (around 240 nm) of poly(pyrAla) in TMP. Conformational analysis based on the ECEPP potential functions and the theoretical CD computation suggested a left-handed a-helical main chain along which the side-chain pyrenyl groups are regularly arranged. 

This paper describes a continuation of the above work, firstly to apply conformational analysis to predict the conformation of the poly(MDI-butandiol) chain, and secondly to extend these x-ray diffraction and model building techniques to investigate the structures formed with other chain extenders, notably propandiol and ethylene glycol. More detailed accounts of this work have been published elsewhere. (11,12)... 

PDO, and EDO preparations (12) are shown in fig. 4. The poly-(MDI-BDO) pattern has been analyzed previously and indicates a triclinic unit cell in which the base plane is tilted, i.e. it is not perpendicular to the fiber axis, such that the chains are in a staggered hydrogen bonded array. The conformational analysis above shows that the polymer chain is fully extended, with the all-trans -(CH2)ij- unit coplanar with the urethane groups. 

The cyclopentane cyclitols have been characterized by nuclear magnetic resonance. The conformational analysis of cyclopentene and of poly-substituted cyclopentanes has been discussed. 

Le Cam E, Pack F, Menissier de Murcia J et al. Conformational analysis of a 139 bp DNA fr -ment containing a single stranded break and its interaction with human poly(ADP-ribose) polymerase. J Mol Biol 1994 235 1062-1071. 

Conformational analysis predicts that the general class of polyesters based on the substituted poly(p-propiolactone) backbone will have nearly identical crystalline conformations, that of a 2 helix with a periodicity of 6 A. The planar zigzag conformation is also energetically allowed, with low energy barriers separating the two conformations . 

The crystal structure of PHB is a orthorhombic form with unit cell parameters fl = 0.576 nm, = 1.320 nm, and c(fiber axis)=0.596 nm, and space group P2,2,2, (Alper et al. 1963 Okamura and Marchessault 1967). The conformational analysis by intermolecular energy calculation has indicated that the PHB molecule has a left-handed 2j helix conformation (Comibert and Marchessault 1972 Yokouchi et al. 1973 Bruckner et al. 1988). The crystal structure of random copolymers of 3HB and 3HV has been investigated extensively (Bloembergen et al. 1986 Kamiya et al. 1991 VanderHart et al. 1995). A structural characteristic of poly(3HB-co-3HV) is isodimorphism, i.e., cocrystallization, of the two monomer units. In contrast, the cocrystallization of 3HB with 3HH or (7 )-6-hydroxyhexanoate (6HH) does not occur. 

Sasanuma, Y., H. Kato, and A. Kaito. 2003. Conformational analysis of poly(di- -butylsilane), poly(di-M-hexylsilane), and poly(methyl- -propylsilane) by a rotational isomeric state scheme with molecular dynamics simulations. J Phys Chem B 107 11852. 

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