The activation of glycogen synthase in hepatocytes from rats with a glycogen storage disorder (gsd/gsd)

A rapid high resolution method of purification of the Trp-containing S100 proteins (S100a, S100a′) and of the S100b protein has been developed. The principle of this method is based on the fact that S100b protein becomes highly hydrophobic upon Zn²⁺ binding, whereas S100a and S100a′ are not affected. On an affinity chromatography of phenyl—Sepharose column, S100b is selectively bound in presence of zinc, whereas the Trp-containing S100 patients are quickly eluted. The S100b protein is further eluted with a buffer containing EDTA.     

Characterization of oligosaccharides of highly purified glycoprotein gC of herpes simplex virus type 1 (HSV-1)

The envelope membrane glycoprotein gC of HSV-1 was purified from Triton X-100 extracts of virus-infected BHK-21 or HEp-2 cells by a single step immuno-affinity column using monoclonal anti-gC antibody. The analysis of the purified [³H]G1cN labeled glycoprotein gC (by gel filtration on Bio-Gel P4) before and after digestion with endo-β-N-acetylglucosaminidase (endo D) indicated that gC contains Asn-linked “complex type” oligosaccharides. No “high mannose” type oligosaccharides were detected. Fractionation of radio-labeled glycopeptides of gC on a column of concanavalin A-sepharose suggested that glycopeptides have “diantennary” and “triantennary” and/or “tetra antennary” structures. Tunicamycin inhibited the incorporation of [¹⁴C]GalN or [³H]GlcN into gC in HSV-1 infected BHK-21 or HEp-2 cells. Gel filtration analysis of [³H]GlcN labeled gC following β-elimination reaction failed to indicate O-glycosidically linked oligosaccharides.     

Glycolytic enzyme binding in fetal brain — The role of actin

The binding of aldolase, glyceraldehyde-3-phosphate dehydrogenase and pyruvate kinase in fetal calf brain homogenates and extracts has been investigated at both 0° and 37°C under high ionic strength conditions. The results demonstrate far greater enzyme binding at 37°C than at 0°C, which correlates with an increased sedimentation of cytoskeletal actin at the higher temperature. A dependence of enzyme sedimentation on the presence of polymerised actin was also demonstrated, and this indicates that cytoskeletal actin is a major adsorbent of glycolytic enzymes in this non-muscle tissue.     

The carbohydrates in frog retinal rod outer segments

Frog retinal rod outer segments appear to contain uncharacterized chemical components whose mass is roughly equivalent to 12--51% of the rhodopsin mass. Available data suggest that such components include soluble proteins and complex polysaccharides, and that hyaluronic acid accounts for a substantial fraction of this mass. Electron microscopic histochemical staining studies suggest that these polysaccharide components are located within the ROS disks. The oligosaccharide moieties of rhodopsin also appear localized within the disks. The interdisk cytoplasm may contain carbohydrates, but their quantity and identity are uncertain. Rhodopsin oligosaccharides as well as some fraction of the intradisk polysaccharide appear to have extended saccharide chains preferentially oriented perpendicular to the surface of the disk membrane. Possible roles for these polysaccharides in disk development and photoexcitation are discussed. The immediate need for complete rod outer segment chemical composition data is emphasized.     

Wax ester formation catalysed by isoenzymes of lipolytic acyl hydrolase

Wax ester formation by esterification of a long chain fatty acid (palmitic acid) with a long chain fatty alcohol (octadecanol) was enzymically catalysed by acetone dried powder preparations of potato tubers. The enzyme responsible for wax ester formation had multiple isoenzymic forms and was identical with lipolytic acyl hydrolase, a lipid deacylating enzyme. Tubers from different varietiees of potato (Solanum tuberosum) demonstrated markedly different levels of activity and electrophoretic patterns for both wax ester formation and lipid deacylation.     

Effect of light source for growth on photosynthetic reactions of Anabaena variabilis particles

Photosynthetic particles were prepared from the blue—green alga Anabaena variabilis grown under two different light conditions. Photosynthetic activity of particles from fluorescent-light-grown cells was lower than that of particles from tungsten-grown cells. The photosynthetic activities of particles from fluorescent-light-grown cells could be increased by moving these cultures to tungsten light. The extent of recovery depended on the ratio of fluorescent growth to the tungsten growth period. It was concluded that the difference in photosynthetic activities between tungsten and fluorescent grown cell-free preparations is more likely due to a lack of red light rather than to disturbance of pigment contents.