Alteration of liver microsomal proteins from rainbow trout (Salmo gairdneri) fed cyclopropenoid fatty acids

Rainbow trout were fed diets containing cyclopropenoid fatty acids (CPFA) at 50 and 300 ppm with appropriate controls fed CPFA-free diets. Treatment with CPFA altered the overall microsomal protein composition in a manner suggesting a reduction of high molecular weight components. One protein found in low concentration in controls appeared dominant in experimental animals, with the effect more pronounced as dietary levels of CPFA increased. The estimated molecular weight of this component was 41,500 daltons. Membrane fractions from CPFA-fed fish separated on a Bio-Gel P-150 column revealed a significant number of small molecular weight components that suggest degradation of microsomal proteins. These data suggest an alteration by CPFA of membrane protein composition.