Bioquímica del ciclo evolutivo del Triatoma infestans (vinchuca). X. Lipoproteinas hemolinfaticas de hembras. / [Biochemistry of the development cycle of Triatoma infestans (vinchuca). X. Hemolymph lipoproteins of females]

ABSTRACT

A lipoprotein of high density (HDL) and three of very high density (VHDL-I, VHDL-f and VHDL-II) were separated by ultracentrifugation from T. infestans female hemolymph. Lipids were mainly transported by HDL, whereas VHDL-II presented the highest protein content. In all the lipoproteins, 1,2 and 1,3-diacylglycerols, triacylglycerols, free fatty acids, cholesterol, cholesterol esters and hydrocarbons, were present. Phosphatidylcholine and phosphatidylethanolamine were also identified. The main lipids were represented by phospholipids, 1,2 and 1,3-diacylglycerols and hydrocarbons. All lipoproteins were delipidated to study the corresponding apolipoproteins. They were examined by SDS-polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol. Apo-HDL was separated into four intense polypeptide bands of approximate MW 19,000; 45,000; 86,000 and 200,000. Apo-VHDL-I was fractionated into three polypeptide bands--a major one of MW 18,500 and two minor ones of 28,000 and 45,000. The apolipoproteins belonging to VHDL-f that only appeared in females, were separated into 10 bands; the major ones corresponded to MW of 58,000, 86,000 and 160,000. In these apolipoproteins, the specimens of 58,000 and 160,000 showed positive carbohydrate reaction. Yet, in the apo-VHDL-II the most intense protein subunits primarily corresponded to bands of MW 160,000 and 86,000. Apparently, the four lipoproteins would share two polypeptide chains.