Publication Abstract

Purification of multiple precursors for egg chorion proteins in Atlantic cod (Gadus morhua)

 T. Fujita, A.P. Scott*, I. Katsiadaki*, H. Amano, L. Hong, N. Hiramatsu, T. Todo, A. Hara

Egg chorion precursors (zona radiata proteins; Zrps) were purified from the blood plasma of female Atlantic cod (Gadus morhua) by salting-out and column chromatography. The salting-out procedure employed a relatively low (30%) concentration of saturated ammonium sulfate. This was a critical step that separated Zrps from approximately 89% of other plasma proteins. Subsequently, three subtypes of Zrp (Zrp-alpha, -beta and -gamma) were purified by four (Zrps-alpha, -gamma) or five (Zrp-beta) serial column chromatography steps. The Intact masses of purified Zrp-alpha, -beta and -gamma were 290 kDa, 134 kDa, and 73 kDa, while masses estimated by SDS-PAGE were 78 kDa, 54 kDa, and 47 kDa, respectively. Antibodies were prepared against Zrp-beta and -gamma and utilized to develop specific immunoassays. The plasma levels of Zrp-beta and -gamma In reproductive female cod were estimated to be 591.42+/-77.59 microg/ml and 768.71+/-120.39 microg/ml, respectively. Thus, practical procedures for the separation of Zrp subtypes were developed in cod, which resulted in the development of subtype-specific Zrp immunoassays in this species; a similar method could be adopted for the separation, detection, and quantification of Zrp subtypes in other teleosts.

Reference

T. Fujita, A.P. Scott, I. Katsiadaki, H. Amano, L. Hong, N. Hiramatsu, T. Todo, A. Hara (2009) Purification of Multiple Precursors for Egg Chorion Proteins in Atlantic Cod (Gadus morhua). Zoological Science 26(12):870-877