A. Takénaka, M. Ohki, Y. Sasada
Oct 1, 1980
Citations
0
Influential Citations
17
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Crystals of cytosine: N,N-phthaloyl-DL-glutamic acid complex dihydrate were obtained from an aqueous solution of the two components. The space group is P21/c with unit-cell dimensions of a=5.243(1), b=39.133(6), c=9.192(1) A, β=93.66(1)°, and Z=4. The structure was solved by the direct method and its parameters were refined by a block-diagonal least-squares method. The complex is formed by the two hydrogen bonds between the oxygen atoms of the ionized α-carboxyl group of glutamic acid and the nitrogen atoms, N(4) and protonated N(3), of cytosine. This binding mode is the same as that found in cytidine: N-benzyloxycarbonyl-L-glutamic acid complex, but quite different from that of 5-bromocytosine: N-acylglutamic acid complexes. The substituted bromine atom at C(5) of cytosine is thought to prescribe the binding mode in complex formation. The binding mode between cytosine and glutamic acid, which might be a possible elementary pattern of protein: nucleic acid interactions, is discussed in terms of dissociati...