این سایت در حال حاضر پشتیبانی نمی شود و امکان دارد داده های نشریات بروز نباشند
Physical Chemistry Research، جلد ۳، شماره ۱، صفحات ۶۷-۷۷
عنوان فارسی
چکیده فارسی مقاله
کلیدواژه‌های فارسی مقاله
عنوان انگلیسی Secondary Structure Effects on the Acidity of Histidine and Lysine-Based Peptides Model; A Theoretical Study
چکیده انگلیسی مقاله In this study, the effect of the secondary structure of the protein on the acid strength of three structures of random (R), alpha helix (α) and beta sheet (b) were investigated theoretically. These structures are related to the cationic amino acids of histidine and lysine in the polypeptide chain of eight-glycine residue. Computational methods at the HF, B3LYP, X3LYP and M05-2X levels in the gas and solution phases were applied. Implicit CPCM solvation model and explicit 2-layer ONIOM methods for the computations in solution were used with the 6-31G (d) basis set. Comparison of pKa values ​​of histidine-based peptide shows that acid strength is accorded to: b > α > R, while in the case of lysine, acid strength is accordance to: α > b > R. Based on the obtained data, ONIOM method is unable to predict the pKa values in the explicit solvation model. NBO analysis showed that one of the main reasons for the increase in the acidity of the solution phase is the increase in delocalization energy difference (ΔEdelocal) of the neutral acid and the corresponding cation. Topological analysis of quantum theory of atoms in molecules for the electron charge density at the bond critical points of the hydrogen bonds of the secondary structures in the presence of the solvent does not show a meaningful correlation with the interaction energy or acid strength. The absolute average ratio of 1.37 and 1.34 for the kinetic energy density to the local potential energy density of lysine and histidine-based peptides, respectively, reveals the non-covalent nature of the O…H bonds. Finally, based on the obtained results, pKa of the proteins can be predicted as a function of hydrogen bond characters and their delocalization energy differences between the cationic and neutral forms.
کلیدواژه‌های انگلیسی مقاله
نویسندگان مقاله محمد ایزدیار |
ferdowsi university of mashhad
سازمان اصلی تایید شده: دانشگاه فردوسی (Ferdowsi university)

محمدرضا حسین دخت | mohammad reza
ferdowsi university of mashhad
سازمان اصلی تایید شده: دانشگاه فردوسی (Ferdowsi university)

ندا زوار |
ferdowsi university of mashhad
سازمان اصلی تایید شده: دانشگاه فردوسی (Ferdowsi university)

محمد خوانی |
ferdowsi university of mashhad
سازمان اصلی تایید شده: دانشگاه فردوسی (Ferdowsi university)

عادل رییسی وانانی | reisi vanani
kashan university
سازمان اصلی تایید شده: دانشگاه کاشان (Kashan university)

نشانی اینترنتی http://www.physchemres.org/article_7693_dd898c8d4fc05b040e7b50549d550e8a.pdf
فایل مقاله اشکال در دسترسی به فایل - ./files/site1/rds_journals/529/article-529-334201.pdf
کد مقاله (doi)
زبان مقاله منتشر شده en
موضوعات مقاله منتشر شده
نوع مقاله منتشر شده
برگشت به: صفحه اول پایگاه   |   نسخه مرتبط   |   نشریه مرتبط   |   فهرست نشریات