eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-01-07 1 2 97 104 3397 article Rabeeth M. 1 Thangarj T 1 Karaiyan K. 1 K. Logan Kumar 1 Kongunadu Arts and Science College, Coimbatore- 641 029 (India) Phenoloxidase in the cuticle was extracted in different stages of development. Maximum enzyme activity was found at the pharate pupal stage (126 ± 4 hr). Extracted enzyme was partially purified using Sephacryl S-400. Two fractions have been localized in 7-18 and 20-24. Partially purified phenoloxidase was localized in the SDS-PAGE. It is resolved that two molecular species of 204 and 230 Kd has been localized. DDC and PTU inhibited the enzyme maximum when compare to PHZ, SA and SF. The enzyme was thermostable upto 40°C and activity showed a broad spectrum of pH. In situ treatment of newly ecdysed puparial cuticle with phenylthiourea inhibited brown colour pigment formation. https://www.biotech-asia.org/vol1no2/purification-and-inhibition-of-cuticular-phenoloxidase-in-the-cotton-bollworm-helicoverpa-armigera-h-lepidoptera/ Cuticle; Phenoloxidase; H. armigera