EFFECTS OF L-GLUTAMYL PEPTIDES ON THE GROWTH OF L-GLUTAMIC ACID CRYSTALS (ALPHA-FORM)

The effects of five gamma-L-glutamyl peptides, two alpha-L-glutamyl pe ptides, and L-phenylalanine (L-Phe) on the growth of {111} and {001} f aces of the alpha-form of L-glutaminic acid (L-Glu) crystals were inve stigated. All the gamma-L-glutamyl and alpha-L-glutamyl peptides and L -Phe had inhibitory effects on the growth of the {111} face, but gamma -Glu-Glu, gamma-Glu-epsilon-Lys, and Glu-Glu suppressed not only the { 111} faces but also the {001} faces. Thus, the distribution of additiv es on the {111} and {001} faces of L-Glu crystals was analyzed. Result s showed that the {001} face of L-Glu crystals had higher concentratio ns of gamma-Glu-Glu, gamma-Glu-epsilon-Lys, and Glu-Glu than other pep tides. The effect of gamma-Glu-Glu on inducing the beta-form is consid ered to be closely related to its specific character of inhibiting the growth of both the {111} and {001} faces of the alpha-form. These phe nomena are discussed on the basis of the crystal structure.