Hoppe-Seyler's Zeitschrift fuer Physiologische Chemie, , vol. 37, p. 54,69, 71 Journal of the American Chemical Society, , vol. 68, p. 2473,2475 Journal of Biological Chemistry, , vol. 172, p. 717,723 Justus Liebigs Annalen der Chemie, , vol. 459, p. 96