Studies on the structure of a novel peptide antibiotic, K‐582

Abstract

A novel peptide antibiotic, K‐582, which exhibited significant growth inhibition of Candida, viruses and ascites tumor in mice, was found in the culture medium of a strain of Metarhizium anisopliae by Kondo et al. (J. Antibiotics33, 535–542 (1980)]. K‐582 consisted of two components, designated K‐582 A and K‐582 B. Threonine, tyrosine, ornithine, and an unusual amino acid were common in both peptides, but lysine was an extra component of K‐582 A. The unusual amino acid was identified to be threo‐γ‐hydroxy‐L‐arginine (OHArg) by means of mass, nuclear magnetic resonance and infrared spectrometries of the derivatives and the related compounds. The threonine and the arginine were assigned to be L‐configuration, and the ornithine and the tyrosine to be D‐configuration in both K‐582 A and K‐582 B, and the lysine to be L‐configuration by comparison of their optical rotatory dispersion spectra with those of standard amino acids. The elucidation of primary structure revealed that they were closely related heptapeptides with the following sequence: K‐582 A:H‐Arg‐OHArg‐Orn‐Thr‐Orn‐Lys‐Tyr‐OH; K‐582 B:H‐Arg‐OHArg‐Orn‐Thr‐Orn‐OHArg‐Tyr‐OH, and had the identical sequence in terms of the configuration of their constituents, namely L‐L‐D‐L‐D‐L‐D.

Characterization of a Citrulline 4‐Hydroxylase from Nonribosomal Peptide GE81112 Biosynthesis and Engineering of Its Substrate Specificity for the Chemoenzymatic Synthesis of Enduracididine

“…Additionally 4-hydroxyarginine can also be found in several peptide antibiotics,s uch as argimicins Aa nd B, [18] and K-582. [19] To this end, we performed sequential site-directed mutagenesis to incrementally incorporate the guanidine binding sequence of VioC or OrfP into GetI (Figure 3). Towards aV ioC-like enzyme,mutation T258D ("DAD") led to a2-fold reduction in total turnover number (TTN) for Cit hydroxylation and am arginal increase in TTN for Arg hydroxylation.…”

“…This mixture proved to be problematic to carry forward for subsequent manipulations.A saw orkaround, we elected to first selectively protect the a-amino group as the corresponding Boc derivative (Scheme 1A). Tr eatment [19] of 9 with N 2 H 4 afforded clean removal of the guanidine side chain to provide N 2 -Boc-4-OH-l-ornithine (10). In contrast, these conditions proved unreactive for removing the ureido group of Cit.…”

Bioinformatics-Guided Discovery of Citrulline 4-Hydroxylase from GE81112 Biosynthesis and Rational Engineering of Its Substrate Specificity

“…Additionally 4hydroxyarginine can also be found in several peptide antibiotics, such as argimicins A and B, 17 and K-582. 18 To this end, we performed sequential site-directed mutagenesis to incrementally incorporate the guanidine binding sequence of VioC or OrfP into GetI (Figure 3). Towards a VioC-like enzyme, mutation T258D ('DAD') led to a 2-fold reduction in total turnover number (TTN) for Cit hydroxylation and a marginal increase in TTN for Arg hydroxylation.…”

“…20 Finally, use of Mitsunobu conditions 21 (DIAD, PPh3) on 16 effected an intramolecular displacement of the secondary alcohol by the pendant guanidine to complete the synthesis of a dipeptide fragment of enduracidin (17). To test the versatility of this methodology, 12 was submitted to the same AlMe3-assisted coupling conditions with H-L-Orn(Z)-OtBu (18) as the reaction partner. Smooth formation of dipeptide 19 could be realized in 71% isolated yield.…”

Isolation and Structure of Another Β‐melanotropin From Salmon Pituitary Glands

“…In our extensive studies of salmon pituitary hormones, it has been recognized that these hormones, except for ACTH and 0-LPH, secreted from pars distalis were predominant in the whole pituitary extract of the teleost. We have isolated and elucidated the primary structures of two EPs (Kawauchietd., 1979(Kawauchietd., , 1980a), a-MSH, b-MSH and corticotropin like intermediate lobe peptide (Kawauchi et al, 1980b) acetone extract of the pituitary of chum salmon, Oncorhynchus keta. It should be emphasized that the teleost pituitary contains two characteristic EPs, which cannot fall into a category of partial sequence of 0-EP, such as a-and yEPs (Guillemin et al, 1976).…”