Urbani R, Di Blas A, Cesàro A
Department of Biochemistry, Biophysics and Macromolecular Chemistry, University of Trieste, Italy.
Int J Biol Macromol. 1993 Feb;15(1):24-9. doi: 10.1016/s0141-8130(05)80084-4.
Potential energy functions evaluating both repulsive-attractive van der Waals non-bonding interactions and electrostatic interactions have been used to evaluate the conformational energies of the repeating units of the kappa-carrageenan polymers. Structural parameters have been obtained by minimization MNDO procedures (MOPAC). Energy maps have been calculated for the (1-3) alpha-D-galactose-4-sulphate (GS) and the (1-4)-3,6-anhydro-alpha-D-galactose (A) residues, taking into account the conformational freedom of the sulphate group. The configurational statistics of the random coiled kappa-carrageenan chain have been explored, disclosing a highly flexible character, which can mainly be ascribed to the random occurrence of two different conformers of the GS-A dimeric unit.
评估排斥-吸引范德华非键相互作用和静电相互作用的势能函数已被用于评估κ-卡拉胶聚合物重复单元的构象能。结构参数通过MNDO程序（MOPAC）最小化获得。考虑到硫酸根基团的构象自由度，已计算出(1-3)α-D-半乳糖-4-硫酸盐（GS）和(1-4)-3,6-脱水-α-D-半乳糖（A）残基的能量图。已探索了无规卷曲κ-卡拉胶链的构型统计，揭示了其高度灵活的特性，这主要可归因于GS-A二聚体单元两种不同构象的随机出现。
