Crustacean immunity. Antifungal peptides are generated from the C terminus of shrimp hemocyanin in response to microbial challenge.
We report here the isolation from plasma of two penaeid shrimp species of novel peptides/polypeptides with exclusive antifungal activities. A set of three molecules was purified with molecular masses at 2.7 kDa (Penaeus vannamei), 7.9 kDa, and 8.3 kDa (Penaeus stylirostris). Primary structure determination was performed by a combination of Edman degradation and mass spectrometry. The peptides display 95-100% sequence identity with a C-terminal sequence of hemocyanin, indicating that they are cleaved fragments of the shrimp respiratory protein. Specific immunodetection of the hemocyanin-derived (poly)peptides revealed that experimental microbial infections increase their relative concentration in plasma as compared with nonstimulated animals. Thus, the production of antifungal (poly)peptides by limited proteolysis of hemocyanin could be relevant to a shrimp immune reaction that would confer a new function to the multifunctional respiratory pigment of crustaceans.
Destoumieux-Garzón
D
D
IFREMER/CNRS/Université de Montpellier 2, UMR 5098, "Défense et Résistance chez les Invertébrés Marins," CC 80, 2 Place Eugène Bataillon, Montpellier 34095, France.
Saulnier
D
D
Garnier
J
J
Jouffrey
C
C
Bulet
P
P
Bachère
E
E
D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000378:metabolism*; D001681:Biological Assay; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D003445:Crustacea / Q000276:immunology*; D033364:Decapoda / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D019075:Electrophoresis, Capillary; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006433:Hemocyanins / Q000737:chemistry* / Q000276:immunology; D006458:Hemolymph / Q000737:chemistry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
D000935:Antifungal Agents; D010455:Peptides; D006433:Hemocyanins