物理化学学报2002，Vol.18Issue(10)：871-877,7.
"D和L-丙氨酸宇称破缺能差正负"的争论
A Debate on the Parity-Violating Energy Difference of D- and L-Alanine
摘要
Abstract
The chiral purity of biochemical monomers only L-amino acids are present in proteins and D-sugars in the DNA and RNA of living organisms is today accepted as an absolute necessity for the existence of life. All previous studies on amino acids reported the naturally occurring L-form to be stabilized by weak neutral currents.Two recent papers dealing with electroweak quantum calculations of the parity-violating energy shifts of alanine in gaseous phase and in solution have defied this long held belief. The parity-violating energy difference (PVED) of Dand L-alanine was undertaken as a function of the dihedral angle θ of the carboxylate plane with respect to the Cα-Hα plane. Dihedral angles was calculated from the atomic coordinates of O(1) O(2) C(1) C(2) H(1) of Dand L-alanine under the temperature dependence of X-ray diffraction data. According to Quack's theoretical results by means of highest level ab initio studies (MC-LR), the △Epv value is 1.2 × 10-19 Hartree (3. 3 × 10-18 eV/molecule), namely L-alanine is more stable than D-alanine. The present paper proved definitely that in the single crystal state L-alanine is lower in energy than D-alanine both by X-ray diffraction data and the differential scanning calorimetry.关键词
宇称破缺能差/D-和L-丙氨酸/二面角/二级相变/X射线四圆单晶衍射Key words
Parity-violating energy difference/D- and L-alanine/Dihedral angle/Second order phase transition/X-ray diffraction分类
化学化工引用本文复制引用
王文清,孙琳,闵玮,王哲明.."D和L-丙氨酸宇称破缺能差正负"的争论[J].物理化学学报,2002,18(10):871-877,7.基金项目
国家863基金资助项目(863-103-13-06-01)和秦惠君-李政道大学生研究基金 （863-103-13-06-01）
