A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein samples

Seeds: Physiology of Development and Germination.

Assay of proteins in the presence of interfering materials.

Both glutathione and an NADPH-dependent glutathione reductase are present in spinach (Spinacia oleracea L.) chloroplasts. It is proposed that glutathione functions to stabilise enzymes of the Calvin cycle, and it may also act to keep ascorbic acid in chloroplasts in the reduced form.

The presence of glutathione and glutathione reductase in chloroplasts: A proposed role in ascorbic acid metabolism.

This overview compiles the actual knowledge of the biogenic emissions of some volatile organic compounds (VOCs), i.e., isoprene, terpenes, alkanes, alkenes, alcohols, esters, carbonyls, and acids. We discuss VOC biosynthesis, emission inventories, relations between emission and plant physiology as well as temperature and radiation, and ecophysiological functions. For isoprene and monoterpenes, an extended summary of standard emission factors, with data related to the plant genus and species, is included. The data compilation shows that we have quite a substantial knowledge of the emission of isoprene and monoterpenes, including emission rates, emission regulation, and biosynthesis. The situation is worse in the case of numerous other compounds (other VOCs or OVOCs) being emitted by the biosphere. This is reflected in the insufficient knowledge of emission rates and biological functions. Except for the terpenoids, only a limited number of studies of OVOCs are available; data are summarized for alkanes, alkenes, carbonyls, alcohols, acids, and esters. In addition to closing these gaps of knowledge, one of the major objectives for future VOC research is improving our knowledge of the fate of organic carbon in the atmosphere, ending up in oxidation products and/or as aerosol particles.

Biogenic Volatile Organic Compounds (VOC): An Overview on Emission, Physiology and Ecology

Mitochondria and glyoxysomes from castor bean endosperm. Enzyme constitutents and catalytic capacity.

INTRODUCTION 159 SOURCES OF MICROBODIES: MICROBODY CONSTITUENTS 162 Glyoxysomes...... ....... ........ ... ...... ... ..... 162 Leaf Peroxisomes 164 Microbodies from Other Tissues ...... 164 DISTRIBUTION OF ENZYMES WITHIN MICROBODIES 165 ISOENZYMES IN GLYOXYSOMES AND LEAF PEROXISOMES 166 Isoenzymes of MDH 166 Isoenzymes of Citrate Synthetase 167 Isoenzymes of Aspartate-a.-Ketoglutarate Transaminase 168 FUNCTIONS OF GLYOXYSOMES AND LEAF PEROXISOMES 168 DEVELOPMENT OF MICROBODIES 170 Glyoxysome Biogenesis ..... ,", . . . . . . . . . . . . . . ,. 170 Biogenesis of Leaf Peroxisomes 176 Microbody Transition in Fatty Cotyledons 177 Hormonal Influences 185 CONCLUSIONS , ...... , 186

Microbodies in Higher Plants

The properties of a discrete membranous fraction isolated on sucrose gradients from castor bean endosperm have been examined. This fraction was previously shown to be the exclusive site of phosphorylcholine-glyceride transferase. The distribution of NADPH-cytochrome c reductase and antimycin insensitive NADH-cytochrome c reductase across the gradient followed closely that of the phosphorylcholine-glyceride transferase. This fraction also had NADH diaphorase activity and contained cytochromes b5 and P 450. On sucrose gradients containing 1 mM EDTA this fraction had a mean isopycnic density of 1.12 g/cm3 and sedimented separately from the ribosomes; electron micrographs showed that it was comprised of smooth membranes. When magnesium was included in the gradients to prevent the dissociation of membrane-bound ribosomes, the isopycnic density of the membrane fraction with its associated enzymes was increased to 1.16 g/cm3 and under these conditions the electron micrographs showed that the membranes had the typical appearance of rough endoplasmic reticulum. Together these data show that the endoplasmic reticulum is the exclusive site of lecithin formation in the castor bean endosperm and establish a central role for this cytoplasmic component in the biogenesis of cell membranes.

/pdf/endoplasmic-reticulum-as-the-site-of-lecithin-formation-in-52nrlitprn.pdf

Harry Beevers

Papers

Mitochondria and glyoxysomes from castor bean endosperm. Enzyme constitutents and catalytic capacity.

Microbodies in Higher Plants

Endoplasmic reticulum as the site of lecithin formation in castor bean endosperm

Association of the glyoxylate cycle enzymes in a novel subcellular particle from castor bean endosperm

β Oxidation in Glyoxysomes from Castor Bean Endosperm