The major egg reserve protein from the invasive apple snail Pomacea maculata is a complex carotenoprotein related to those of Pomacea canaliculata and Pomacea scalaris

PASQUEVICH MY,; DREON MS,; HERAS, H.

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART B, BIOCHEMISTRY & MOLECULAR BIOLOGY.

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2014 vol. 169 p. 63 - 71

1096-4959

Many apple snails lay conspicuous masses of brightly colored eggs above the water. The color is provided by carotenoproteins which play important roles in protection against sun radiation, stabilizing and transporting antioxidant molecules and helping to protect embryos from desiccation and predators. They seem a key adaptation of ampullarids but have been little studied. Here we report the characteristics of the major carotenoprotein from Pomacea maculata and the first comparison among these egg proteins. This particle, hereafter named PmPV1, represents approximately 52 % of total periviteline fluid soluble protein. It is a glyco-lipo-carotenoprotein responsible for the bright reddish egg coloration. With characteristics of VHDL, PmPV1 apparent molecular mass is 294 KDa, composed of five non-covalently bound subunits of isoelectric points ranging between 4.7 and 9.8 and masses between 26 and 36 KDa whose N-terminal sequences were obtained. It is scarcely lipidated but highly glycosilated (<1% lipid and 13% carbohydrate, w/w). The lipid component includes phospholipids, free fatty acids and carotenoids; mannose and galactose predominate over other monosaccharides. Main carotenoids are esterified and non-esterified astaxanthin (71 and 25%, respectively). Carotenoid removal does not seem to affect the structural characteristics of the oligomer, while deglycosilation reduces subunit number from five to a single one. The carotenoid?protein association protected the former against oxidation. PmPV1 cross reacts with polyclonal antibodies against PcOvo, the major carotenoprotein from Pomacea canaliculata. The characterization of PmPV1 allows the first comparisons among snail carotenoproteins and further highlights the importance of these perivitellins in the reproductive strategy of Pomacea.