Neocarzinostatin : Selective Tryptophan Oxidation and Neocarzinostatin-Chromophore Binding to Apo-Neocarzinostatin

• Published in: Chemical & pharmaceutical bulletin Vol. 39; no. 1; pp. 170 - 176
• Main Authors: EDO, Kiyoto, SAITO, Kunihito, MATSUDA, Yoshinobu, AKIYAMA-MURAI, Yuriko, MIZUGAKI, Michinao, KOIDE, Yoshio, ISHIDA, Nakao
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 01.01.1991; Maruzen
• Subjects: Amino Acid Sequence; Antibiotics, microbial producers, chemotherapic agents, antiseptics, disinfecting agents; apo-neocarzinostatin; apoprotein-chromophore interaction; Apoproteins - metabolism; Applied microbiology; Biological and medical sciences; Chemotherapic agents; Fundamental and applied biological sciences. Psychology; Microbiology; Molecular Sequence Data; neocarzinostatin; neocarzinostatin-chromophore; Oxidation-Reduction; Protein Binding; selective tryptophan oxidation; Tryptophan - metabolism; Zinostatin - metabolism; Antineoplastic agent; Streptomycetaceae; Interaction; Streptomyces; Tryptophan; Binding site; Actinomycetales; Antibiotic; Microbial origin; Apoproteins; Bacteria; Actinomycetes; Oxidation; Physicochemical properties; Chromophore
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.39.170

Neocarzinostatin (NCS), an antitumor protein antibiotic, is composed of apo-neocarzinostatin (apo-NCS) and neocarzinostatin-chromophore (NCS-chr), the principle of the biological activities of NCS. Apo-NCS having two tryptophan (Trp) residues at positions (39 and 83) was chemically modified by N-bromosuccinimide in a study on the correlation of the binding site(s) of NCS-chr. Selective oxidation of Trp residues was observed when NCS was titrated with N-bromosuccinimide. In contrast, non-selective oxidation of the two Trps on apo-NCS was observed and both Trp (39 and 83) of apo-NCS were titrated with N-bromosuccinimide. After selective oxidization, the remaining Trp residue of NCS was assigned as Trp (83). These results clearly indicate that the Trp (83) residue of apo-NCS changed from the "reactive type" to the "non-reactive type" after the binding of NCS-chr with apo-NCS. The fluorescence emission intensity of apo-NCS generated from the Trp (39) residue was quenched by NCS-chr. These data suggest that NCS-chr directly interacts with the Trp (39) residue and that a β-sheeted loop containing the Trp (83) residue of apo-NCS changes the high-order structure upon binding with NCS-chr.