Subcellular Localization of Amylose Precipitating Factor in Neurospora

1982 ◽  
Vol 40 ◽  
pp. 312-313
Author(s):  
Jacob P. Varkey ◽  
Mathew J. Nadakavukaren ◽  
Derek A. McCracken
Keyword(s):  
Subcellular Localization ◽  
Higher Plants ◽  
Starch Biosynthesis ◽  
Short Chain ◽  
Distinguishing Characteristic ◽  
Fungal Hyphae ◽  
Precipitating Factor

Amylose precipitating factor (APF) is a lipoprotein first found associated with starch in some fungi. Since then, APF has been reported from many organisms. The ability of the lipoprotein to bind to short chain amylose molecules and precipitate them is used as a distinguishing characteristic. Starch produced by certain fungi consists of short chain amylose molecules. Even though these fungi have the enzymes needed for the formation of large amylose molecules as in higher plants, the reason for the formation of short chain amylose is not known. Since APF is associated with short chain amylose molecules, we were interested in studying the effect of APF on the fungal starch biosynthesis. In this paper we describe the localization of APF in the fungal hyphae.

scholarly journals Distribution and sources of n-alkanes in surface sediments of Taihu Lake, China

2016 ◽  
Vol 42 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Yunlong Yu ◽  
Yuanyuan Li ◽  
Zhigang Guo ◽  
Hua Zou
Keyword(s):  
Surface Sediment ◽  
Surface Sediments ◽  
Taihu Lake ◽  
Higher Plants ◽  
Complex Mixture ◽  
Dry Weight ◽  
Short Chain ◽  
Sediment Samples ◽  
Total Concentrations ◽  
Long Chain

Abstract The last study on n-alkanes in surface sediments of Taihu Lake was in 2000, only 13 surface sediment samples were analysed, in order to have a comprehensive and up-to-date understanding of n-alkanes in the surface sediments of Taihu Lake, 41 surface sediment samples were analyzed by GC-MS. C10 to C37 were detected, the total concentrations of n-alkanes ranged from 2109 ng g−1 to 9096 ng g−1 (dry weight). There was strong odd carbon predominance in long chain n-alkanes and even carbon predominance in short chain n-alkanes. When this finding was combined with the analysis results of wax n-alkanes (WaxCn), carbon preference index (CPI), unresolved complex mixture (UCM), hopanes and steranes, it was considered that the long chain n-alkanes were mainly from terrigenous higher plants, and that the short chain n-alkanes mainly originated from bacteria and algae in the lake, compared with previous studies, there were no obvious anthropogenic petrogenic inputs. Terrestrial and aquatic hydrocarbons ratio (TAR) and C21−/C25+ indicated that terrigenous input was higher than aquatic sources and the nearshore n-alkanes were mainly from land-derived sources. Moreover, the distribution of short chain n-alkanes presented a relatively uniform pattern, while the long chain n-alkanes presented a trend that concentrations dropped from nearshore places to the middle of lake.

scholarly journals A fixation procedure suitable for autoradiography of endogenous long-chain acyl carnitine.

1985 ◽  
Vol 33 (8) ◽  
pp. 744-748 ◽  
Author(s):  
M T Knabb ◽  
G G Ahumada ◽  
B E Sobel ◽  
J E Saffitz
Keyword(s):  
Subcellular Localization ◽  
Selective Extraction ◽  
Total Radioactivity ◽  
Water Soluble ◽  
Free Carnitine ◽  
Neonatal Rat ◽  
Short Chain ◽  
Tissue Processing ◽  
Chain Acyl ◽  
Long Chain

A tissue processing procedure was evaluated for fixation of endogenous long-chain acyl carnitine (LCA) to facilitate autoradiographic subcellular localization of this amphiphile. Suspensions of neonatal rat myocytes labeled with exogenous 14C-palmitoyl carnitine retained 85.2% of the radiolabel after tissue processing. Autoradiography demonstrated no significant translocation of radiolabeled LCA from myocytes to unlabeled sheep erythrocytes mixed in equal proportions and processed together. To evaluate endogenous LCA fixation, cultured myocytes were incubated for 3 days with 3H-carnitine. Radioactivity was distributed in LCA, short-chain acyl carnitine, and free carnitine pools in proportion to the physiological concentrations of the metabolites traced. Before tissue processing, LCA contained 4.5% of total radioactivity. After tissue processing, labeled water-soluble components were lost and 88% of the retained radioactivity was in the LCA pool. The enrichment of endogenous LCA radioactivity was attributable to the selective extraction of endogenous short-chain and free carnitine. Nearly 75% of endogenous LCA was preserved. In contrast, 99.5% of both endogenous short-chain and free carnitine were extracted. Thus, endogenous LCA can be selectively preserved, permitting quantitative subcellular localization of this amphiphile with ultrastructural autoradiography.

scholarly journals Molecular Functions and Pathways of Plastidial Starch Phosphorylase (PHO1) in Starch Metabolism: Current and Future Perspectives

2021 ◽  
Vol 22 (19) ◽  
pp. 10450
Author(s):  
Noman Shoaib ◽  
Lun Liu ◽  
Asif Ali ◽  
Nishbah Mughal ◽  
Guowu Yu ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Molecular Mechanisms ◽  
Higher Plants ◽  
Crop Improvement ◽  
Starch Biosynthesis ◽  
Starch Metabolism ◽  
Protein Protein Interactions ◽  
Starch Phosphorylase ◽  
Integral Role

Starch phosphorylase is a member of the GT35-glycogen-phosphorylase superfamily. Glycogen phosphorylases have been researched in animals thoroughly when compared to plants. Genetic evidence signifies the integral role of plastidial starch phosphorylase (PHO1) in starch biosynthesis in model plants. The counterpart of PHO1 is PHO2, which specifically resides in cytosol and is reported to lack L80 peptide in the middle region of proteins as seen in animal and maltodextrin forms of phosphorylases. The function of this extra peptide varies among species and ranges from the substrate of proteasomes to modulate the degradation of PHO1 in Solanum tuberosum to a non-significant effect on biochemical activity in Oryza sativa and Hordeum vulgare. Various regulatory functions, e.g., phosphorylation, protein–protein interactions, and redox modulation, have been reported to affect the starch phosphorylase functions in higher plants. This review outlines the current findings on the regulation of starch phosphorylase genes and proteins with their possible role in the starch biosynthesis pathway. We highlight the gaps in present studies and elaborate on the molecular mechanisms of phosphorylase in starch metabolism. Moreover, we explore the possible role of PHO1 in crop improvement.

Properties and Subcellular Localization of ʟ-Alanine: Aldehyde Aminotransferase: Concept of an Ubiquitous Plant Enzyme Involved in Secondary Metabolism

1981 ◽  
Vol 36 (7-8) ◽  
pp. 625-632 ◽  
Author(s):  
Coralie Wink ◽  
Thomas Hartmann
Keyword(s):  
Subcellular Localization ◽  
Secondary Metabolism ◽  
Spinacia Oleracea ◽  
Higher Plants ◽  
Ph Dependence ◽  
Metabolic Function ◽  
Aliphatic Aldehydes ◽  
Low Levels ◽  
Arum Maculatum ◽  
Plant Enzyme

Abstract L-Alanine: aldehyde aminotransferase occurs ubiquitously in higher plants. The enzyme catalyzes the reaction: L-alanine + monoaldehyde -> monoamine + pyruvate; it is responsible for the formation of aliphatic plant amines and involved in the biosynthesis of hemlock alkaloids as shown by Roberts. A continuous coupled photometric test was developed to determine the low activities of the transaminase. The enzyme from the "amine-free" plant Spinacia oleracea was purified 77-fold and separated from other aminotransferases. A comparison of the Spinacia enzyme with that isolated from spadix-appendices of the amine-producing Arum maculatum during anthesis revealed very similar characteristics in pH-dependence, ATm-values for alanine and aliphatic aldehydes, and inhibition by 2-oxoacids. In contrast to the Spinacia enzyme the Arum aminotransferase is rapidly inactivated in the absence of pyridoxal-5'-phosphate. The enzymes of S. oleracea, A. maculatum and Mercurialis perennis are localized in mitochondria, but not in chloroplasts or peroxisomes. The results are discussed in relation to the function of alanine: aldehyde aminotransferase in secondary metabolism. It is suggested that some enzymes may be expressed in plants at low levels, even in the absence of any metabolic function.

BIOSYNTHESIS AND DEGRADATION OF STARCH IN HIGHER PLANTS

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Higher Plants ◽  
Starch Biosynthesis ◽  
Metabolizing Enzymes ◽  
Transitory Starch ◽  
Leaf Tissues ◽  
Cellular Compartments

Numerous reviews on starch biosynthesis and degradation have appeared inthe 1980s (4, 23, 39, 40, 51, 73, 100, 101, 124, 125). Here we updateestablished concepts and emphasize three topics that we consider to now meritreexamination: the significance of enzyme multiplicity, a comparison ofdegradation of reserve and transitory starch, and the localization of starchdegrading enzymes in starch-free cellular compartments of leaf tissues. Westress the cell physiological aspects of starch metabolizing enzymes.

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