The structure of a prophenoloxidase (PPO) from Anopheles gambiae provides new insights into the mechanism of PPO activation.

ABSTRACT:

Background

Phenoloxidase (PO)-catalyzed melanization is a universal defense mechanism of insects against pathogenic and parasitic infections. In mosquitos such as Anopheles gambiae, melanotic encapsulation is a resistance mechanism against certain parasites that cause malaria and filariasis. PO is initially synthesized by hemocytes and released into hemolymph as inactive prophenoloxidase (PPO), which is activated by a serine protease cascade upon recognition of foreign invaders. The mechanisms of PPO activation and PO catalysis have been elusive.

Results

Herein, we report the crystal structure of PPO8 from A. gambiae at 2.6 Å resolution. PPO8 forms a homodimer with each subunit displaying a classical type III di-copper active center. Our molecular docking and mutagenesis stu

SUBMITTER: Hu Y 

PROVIDER: S-EPMC4700666 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature