scholarly journals Protein biotinylation in higher plants: characterization of biotin holocarboxylase synthetase activity from pea (Pisum sativum) leaves

1996 ◽  
Vol 314 (2) ◽  
pp. 391-395 ◽  
Author(s):  
Ghislaine TISSOT ◽  
Dominique JOB ◽  
Roland DOUCE ◽  
Claude ALBAN
Keyword(s):  
Biochemical Parameters ◽  
Direct Evidence ◽  
Higher Plants ◽  
Carrier Protein ◽  
Synthetase Activity ◽  
Holocarboxylase Synthetase ◽  
Biotin Carboxyl Carrier Protein ◽  
Ammonium Sulphate Fractionation ◽  
Plant Enzyme

Biotin holocarboxylase synthetase was partially purified from pea leaves by a sequence of ammonium sulphate fractionation and DEAE 52-cellulose chromatography. Enzyme activity was assayed using apo-(biotin carboxyl carrier protein) from an Escherichia coli bir A mutant affected in biotin holocarboxylase synthetase activity. Conditions for optimal catalytic activity and biochemical parameters of the plant enzyme were determined. This is the first direct evidence of the existence of biotin holocarboxylase synthetase activity in plants.

The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

1973 ◽  
Vol 31 ◽  
pp. 574-575
Author(s):  
J. T. Stasny ◽  
R. C. Burns ◽  
R. W. F. Hardy
Keyword(s):  
Cellular Localization ◽  
Direct Evidence ◽  
Azotobacter Vinelandii ◽  
Intracellular Localization ◽  
Protein Component ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fe Protein ◽  
Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

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