The trypsin inhibitor panulirin regulates the prophenoloxidase-activating system in the spiny lobster Panulirus argus.

ABSTRACT: The melanization reaction promoted by the prophenoloxidase-activating system is an essential defense response in invertebrates subjected to regulatory mechanisms that are still not fully understood. We report here the finding and characterization of a novel trypsin inhibitor, named panulirin, isolated from the hemocytes of the spiny lobster Panulirus argus with regulatory functions on the melanization cascade. Panulirin is a cationic peptide (pI 9.5) composed of 48 amino acid residues (5.3 kDa), with six cysteine residues forming disulfide bridges. Its primary sequence was determined by combining Edman degradation/N-terminal sequencing and electrospray ionization-MS/MS spectrometry. The low amino acid sequence similarity with known proteins indicates that it represents a new family of pept

SUBMITTER: Perdomo-Morales R 

PROVIDER: S-EPMC3814779 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature