Gumeniuk V A, Sukhorukov B I, Khomenko V G
Biofizika. 1976 Jul-Aug;21(4):597-602.
Effect of water vapour on sublimated films of nucleic acid pyrimidine bases was studied by IR-spectroscopy and X-ray pattern. It is found that freshly deposited films of uracil present a layered amorphous phase, of isocytosine--an amorphous phase; of cytosine--a crystal one. It is shown that water plays the role of an effective catalyzer providing at room temperature rapid transition of isocytosin from amorphous phase, uracyl from the layered amorphous phase into a crystal one. Under the effect of water sorbed molecules of cytosine changes are observed in the IR-spectrum. The latter are most significant in the region of non-plane deformation variations of NH- and NH2-groups. A mechanism of water effect on structural transformations found by us and the growth of nitrous bases crystals is suggested.
通过红外光谱和X射线衍射研究了水蒸气对核酸嘧啶碱基升华膜的影响。发现新沉积的尿嘧啶膜呈现层状非晶相，异胞嘧啶膜呈现非晶相，胞嘧啶膜呈现晶相。结果表明，水起到了有效催化剂的作用，在室温下促使异胞嘧啶从非晶相、尿嘧啶从层状非晶相快速转变为晶相。在胞嘧啶吸附水分子的作用下，红外光谱中出现了变化。这些变化在NH和NH2基团的非平面变形振动区域最为显著。我们提出了水对所发现的结构转变以及亚硝基碱晶体生长的作用机制。
