Digalactosyl diglycerides

These same human sera and some of the rabbit sera also were tested against ceramide trihexoside (CTH) and digalactosyl diglyceride (Table I). Several of the human sera reacted with digalactosyl diglyceride, in confirmation of the results of Hirsch and Parks ( 5). Although only a few human sera reacted with CTH, all of the rabbit sera tested showed reactivity. 

TABLE I. HUMAN AND RABBIT NATURAL ANTIBODIES AGAINST DIGALACTOSYL DIGLYCERIDE AND CERAMIDE TRIHEXOSIDE... 

Substituted pyridazinone herbicides directly inhibit photosystem II, chloroplast pigment biosynthesis, and membrane lipid biosynthesis. Depending on the substitution, pyridazinones can specifically inhibit the synthesis of linolenic acid in galacto-lipids and phospholipids preferentially alter the fatty acid composition of monogalactosyl diglycerides compared with digalactosyl diglycerides and cause a build-up of saturated fatty acids in the chloroplast membranes. 

Wheat flour contains 0.2% free polar lipid,approximately one-half of which is digalactosyl diglycerides (11). Despite their low concentration, free-polar lipids are essential to the breadmaking characteristics of wheat flour (12). Monoesters of sucrose contain the same ratio 6T hexose to fatty acid as found in digalactosyl diglycerides (Figure 1). 

Sastry, P.S. and Kates, M. (1964) Hydrolysis of monogalactosyl and digalactosyl diglycerides by specific enzymes in Runner-Bean leaves. Biochemistry 3, 1280-1287. 

A. Radunz Localization of the Tri- and Digalactosyl Diglyceride in the Thylakoid Membranewith Serological Methods. Z. Naturforsch. 31c 589 (1976)... 

Gadner HW. Preparative isolation of monogalactosyl and digalactosyl diglycerides by thin layer chromatography. J Lipid Res 1968 9 139-41. 

LIST OF ABBREVIATIONS ACP, acyl carrier protein 5ALA, 5-aminolevulinic acid AU, 6-azauracyl CAP, chloramphenicol CHI, cycloheximide DCIP, 2,6-dichlorophenolindo-phenol DCMU, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea DG, digalactosyl-diglyceride DPC, diphenylcarbazide ETS, electron-transport system FDPase, alkaline fructose 1,6-diphosphate phosphatase G-3-P, glyceraldehyde-3-phosphate MG, monogalactosyldiglycer-ide PSI, PSII, photosystems I and II P700, active center of photosystem I PMS, phenazine methosulfate Q, photosystem II quencher Ru-l,5-diP, ribulose-1,5-diphosphate SDS, sodium dodecylsulfate SL, sulfolipid. 

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