Title: Leupeptins

Literature References: Class of modified tripeptide protease inhibitors produced by various species of Actinomycetes. Two major components, leupeptin Ac-LL and leupeptin Pr-LL, consisting of L-leucyl-L-leucyl-DL-argininal modified at the amino terminal by acetyl- or propionyl-, respectively, have been isolated. Various minor analogs, in which valine or isoleucine replaces either or both leucines, have also been found. Isolation from Actinomycetes: T. Aoyagi et al., J. Antibiot. 22, 283 (1969); S.-I. Kondo et al., Chem. Pharm. Bull. 17, 1896 (1969). Structure and synthesis of leupeptins Ac-LL and Pr-LL: K. Kawamura et al., ibid. 1902; K. Maeda et al., J. Antibiot. 24, 402 (1971). Improved purification of leupeptin Ac-LL: M. C. Y. Ning, R. J. Beynon, Int. J. Biochem. 18, 813 (1986). Inhibition of proteases: T. Aoyagi et al., J. Antibiot. 22, 558 (1969); and synthesis of analogs: G. Borin et al., Z. Physiol. Chem. 362, 1435 (1981). Effects on protein degradation in normal and diseased muscle: P. Libby, A. L. Goldberg, Science 199, 534 (1978); I. Nonaka et al., Acta Neuropathol. 58, 279 (1982); R. P. Hummel, III et al., J. Surg. Res. 45, 140 (1988). HPLC determn of leupeptin Ac-LL in serum and muscle: M. Kai et al., J. Chromatogr. 345, 259 (1985).

NOTE: In some sources leupeptin refers only to leupeptin Ac-LL.

Use: Enzyme inhibitor in biological preparations.