CAJ | 학술논문

利用原子力显微镜(AFM)成像技术来观察DL-缬氨酸晶体表面分子的规则排列,研究表明对映体分子在DL-缬氨酸晶体中相互配对排列,每个晶胞单元中包含两个对映体分子,属于具有中心对称结构P1群,整个晶体是消旋的.通过原子力显微镜对DL-缬氨酸晶体表面重复单元的测量结果与X衍射数据对比,发现用AFM观察到的DL-缬氨酸晶体中分子表面形貌的规整排列的距离,同X衍射得出的三斜晶系晶胞参数数据基本一致,由此判定该晶体属于三斜晶系而不是单斜晶系.探讨了利用纳米技术的研究手段在分子水平研究生命起源中的手性问题,在确定的晶面上通过分子周期性结构排列规律,对DL-缬氨酸晶体表面分子进行手性识别.
이용원자력현미경(AFM)성상기술래관찰DL-힐안산정체표면분자적규칙배렬,연구표명대영체분자재DL-힐안산정체중상호배대배렬,매개정포단원중포함량개대영체분자,속우구유중심대칭결구P1군,정개정체시소선적.통과원자력현미경대DL-힐안산정체표면중복단원적측량결과여X연사수거대비,발현용AFM관찰도적DL-힐안산정체중분자표면형모적규정배렬적거리,동X연사득출적삼사정계정포삼수수거기본일치,유차판정해정체속우삼사정계이불시단사정계.탐토료이용납미기술적연구수단재분자수평연구생명기원중적수성문제,재학정적정면상통과분자주기성결구배렬규률,대DL-힐안산정체표면분자진행수성식별.
Atomic force microscopy(AFM) has been used to image arrays of molecules at the surface of DL-valine crystals. AFM images of DL-valine show that D- and L- molecular pairs formed from a DL-racemic mixture are exclusively homochiral. There are two different conclusions about the crystal structure of DL-valine with the data of X-ray crystallography. First, the structure of DL-valine was solved in the monoclinic space group P21/c. Second, the crystal structure of DL-valine has been refined in the centrosymmetric space group P1 and indicated a triclinic rather than a monoclinic space group. The present work emphasizes to solve the contradicting observations of space group and to provide direct evidence for chiral recognition at molecular level. DL-valine molecules {001 } are all in zwitterionic form with the isopropyl groups close to the surface and methyl groups on the top site, showing an ordered molecular morphology of triclinic unit cells, which are in fair agreement with the X-ray diffraction data. The application of AFM to the investigation of protein' s origins and a molecular-level illustration of chiral recognition at a periodic 2D surface structure ofracemic crystals is discussed.