... a-KB(y) (A) , , I I --l..---L.- " « , 4.0 3.8 3.6 3.4 2.8 2.6 2.2 2.0 1.2 1.0 Chemical shift (ppm) FIG. ... York, NY, 1975, p. 457. 2) H. Tanaka, N. Esaki and K. Soda, Biochemistry, 16, 100 (1977). 3) H. Tanaka, N. Esaki, T. Yamamoto and K. Soda, FEBS Lett., 66, 307 (1976). ... Chem. Soc. ...