Applicability of Native L-Arginase produced by Streptomyces plicatus KAR73 as Antineoplastic Agent

Abstract

Most of the cancer cells require high quantity of arginine for sustaining their fast-metabolic rates. Limiting supply of arginine to cancer cells using arginase may prove to be of great therapeutic value. The arginase produced by a micro organism isolated from soil has been used in industrial production of ornithine, however its use in anticancer activities is scarcely studied. This study optimized soybean meal supplemented basal media for Arginase production. Arginase was purified using ammonium sulphate precipitation, sephadex G-100 column chromatography and DEAE chromatography achieving 79.2% purification fold and 24.26% yield. It had 23 KD molecular weight as determined using Native PAGE and was active at considerably wide pH range of 6–10 and temperature 30–50℃. Whereas the maximum arginase activity was noticed with Mn²⁺ ions followed by polyvinyl pyrrolidine (PVP) at 70 mM substrate concentration, the maximum inhibition of activity was caused by CuC. Streptomyces plicatus KAR 73 produced arginase on mouse mammary cell line (CID 9) was not inhibited by the arginase upto 6.5 U/mL. Significant (p< 0.001) inhibition in Mouse mammary tumor (C1271) cell lines was observed with IC₅₀ 5.2 U/mL. The ornithine has been produced earlier with Mycoplasma and Clostridium by other researchers but production of native arginase from Streptomyces specifically for anticancer activities has not yet been reported. The present study infers that Arginase produced from native Streptomyces has shown promising results thereby enabling feasibility assessment towards cost effective industrial production of arginase.