کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5191239 1381228 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Theoretical study of temperature induced phase transitions in poly(β-benzyl-l-aspartate) and it's copolymer
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Theoretical study of temperature induced phase transitions in poly(β-benzyl-l-aspartate) and it's copolymer
چکیده انگلیسی

In polypeptides and proteins, the phenomenon of conformational transitions has been successfully explained on the basis of Zimm and Bragg model, as a function of temperature, pressure, solvent concentration and pH etc. The Zimm and Bragg theory of helix↔coil transition has been modified to explain the temperature induced helix→helix transitions in solid films of poly(β-benzyl-l-aspartate) and in its copolymer copoly(β-stearyl-l-aspartate-β-benzyl-l-aspartate) with varying degrees of stearylation. An expression for the degree of order is obtained from the grand partition function for the entire chain in terms of nucleation parameter, which controls the transition width. At low degree of stearylation, an α→ω transition occurs with the increase in temperature, whereas, at degree higher than 40%, the reversal of α helix sense from right-handed to left-handed takes place. The theoretical transition curves are found to be in good agreement with the experimental data.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 18, 23 August 2005, Pages 7450-7455
نویسندگان
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