Title: Tonin
CAS Registry Number: 53414-68-9
Additional Names: b-Angiotensin I converting enzyme (formerly)
Literature References: A converting enzyme that differs from renin, q.v., in its ability to form angiotensin II directly from angiotensinogen by cleaving the Phe-His bond; it can also convert angiotensin I to angiotensin II. Its presence was discovered in rat submaxillary glands: R. Boucher et al., Hypertension 72, J. Genest, E. Koiw, Eds. (Springer-Verlag, New York, 1972) p 512; eidem, Circ. Res. Suppl. I, 203 (1974). Purification and characterization: S. Demassieux et al., Can. J. Biochem. 54, 788 (1976). Crystal data: K. Hayakawa et al., J. Mol. Biol. 123, 107 (1978). Radioimmunoassay: J. Gutkowska et al., Can. J. Biochem. 56, 769 (1978). Purification by affinity chromatography: M. Ikeda et al., Hypertension 3, 81 (1981); by gel permeation and HPLC: C. Lazure et al., Anal. Biochem. 125, 406 (1982). Isoln using chromatofocusing: E. S. P. Cheng, B. J. Morris, ibid. 126, 295 (1982). N-Terminal amino acid sequence of rat tonin: N. G. Seidah et al., Can. J. Biochem. 56, 920 (1978). Substrate specificity studies: eidem, Proc. Am. Peptide Symp. 6th, E. Gross, J. Meienhofer, Eds. (Pierce Chem. Co., Rockford, Ill., 1979) p 921; M. Chretien et al., FEBS Lett. 113, 173 (1980). Formation of angiotensin II by tonin from partially purified human angiotensinogen: C. Grise et al., Can. J. Biochem. 59, 250 (1981). Pressor effect in anephric animals: E. L. Schiffrin et al., Can. J. Physiol. Pharmacol. 59, 864 (1981). Sequence homologies between tonin and other peptides: C. Lazure et al., Nature 292, 383 (1981). Immunohistochemical study: T. B. Oerstavik et al., J. Histochem. Cytochem. 30, 1123 (1982). Role as renin activator: J. Gutkowska et al., Can. J. Biochem. 60, 843 (1982). Role in exptl hypertension: R. Garcia et al., Hypertension, Int. Symp., 3rd, H. Villarreal, Ed. (Wiley, New York, 1981) p 79. Reviews: R. Boucher et al., Circ. Res. Suppl. II, 26-29 (1977); R. Boucher, J. Genest, Endocrine Functions of the Brain, M. Motta, Ed. (Raven Press, New York, 1980) pp 373-384; J. Genest, Heterogeneity of Renin and Renin Substrate, M. P. Sambhi, Ed. (Elsevier, New York, 1981) pp 11-24.
Properties: Mol wt determn is 31,400 by gel filtration and 28,700 by sedimentation equilibrium. Activity is not affected by pepstatin. Can be incubated at 20° for 150 min, between pH 3.4-8 without significant loss of enzymatic activity; loses 15% of its original activity at pH 2.8. After 5 min of incubation at 100°, 60-65% activity remains. |