Pohle W, Fritzsche H
Nucleic Acids Res. 1976 Dec;3(12):3331-5. doi: 10.1093/nar/3.12.3331.
Infrared linear dichroism (LD) measurements on films of the DNA-caffeine complex in terms of the relative humidity (r.h.) show two main effects. Firstly, there is an insertion of caffeine molecules into the DNA double helix (B form), as evidenced by a very strong parallel LD behaviour of the 745 cm-1 band due to the C-H out-of-plane deformation vibration of caffeine. Furthermore, a high r.h. values a modified B form occurs in the complex similar to the B form recently reported by BRAHMS and coworkers for DNA-polypeptide complexes. The reversible B-A transition of the DNA in dependence of the r.h. is not affected in general in the presence of caffeine.
对DNA - 咖啡因复合物薄膜进行的红外线性二色性(LD)测量,以相对湿度(r.h.)为条件,显示出两种主要效应。首先,咖啡因分子插入到DNA双螺旋(B型)中,这由咖啡因C - H面外变形振动引起的745 cm⁻¹谱带的非常强的平行LD行为所证明。此外,在高相对湿度值时,复合物中会出现一种类似于BRAHMS及其同事最近报道的DNA - 多肽复合物的B型的修饰B型。DNA的可逆B - A转变一般不受咖啡因存在的影响。