Biochemistry 16(1):100;1977; Biochemistry 18(21):4690;1979; Biochemistry 18(3):407;1979; Cancer Res 33(8):1862;1973; Cancer Res 33(8):1866;1973; Cancer Treat Rep 63(6):1069;1979; FEBS Lett 84(2):309;1977; J Biochem (Tokyo) 78:1105;1975; J Biochem (Tokyo) 80(6):1327;1976