Lipoprotein and apoprotein profile of Japanese quail

The present study delineated the lipoprotein and apoprotein distribution in Japanese quail. Quail lipoprotein was composed of three fractions: VLDL, d < 1.020; LDL, 1.020 < d < 1.081; HDL, 1.081 < d < 1.210. When animals were fed the cholesterol-free diet, HDL was the predominant form, LDL intermediate, VLDL and chylomicron were smallest in amount. Feeding of cholesterol induced a marked change in the lipoprotein profile: VLDL or chylomicron predominated over HDL and LDL. An apoprotein of 26 kD (molecular weight) was the major protein moiety comprising more than 50% of total apoprotein in the entire density range of lipoprotein class. Amino acid composition of 26 kD protein was similar to hen, rat and human apo A-I. N-Terminal 36 amino acid sequence of 26 kD protein showed 92% homology to chicken apo A-I and 11% homology to human apo A-1. The 26 kD protein did not react with the antibody raised against human apo A-I. These observation showed that the 26 kD protein was partially identical to apo A-I.