Plant holo-(acyl carrier protein) synthase.
1. An improved method was developed for the assay of plant holo-(acyl carrier protein) synthase activity, using Escherichia coli acyl-(acyl carrier protein) synthetase as a coupling enzyme. 2. Holo-(acyl carrier protein) synthase was partially purified from spinach (Spinacia oleracea) leaves by a combination of (NH4)2SO4 fractionation and anion-exchange and gel-permeation chromatography. 3. The partially purified enzyme had a pH optimum of 8.2 and Km values of 2 microM, 72 microM and 3 mM for apo-(acyl carrier protein), CoA and Mg2+ respectively. Synthase activity was inhibited in vitro by the reaction product 3',5'-ADP. 4. Results from the fractionation of spinach leaf and developing castor-oil-seed (Ricinus communis) endosperm cells were consistent with a cytosolic localization of holo-(acyl carrier protein) synthase activity in plant cells.
Elhussein
S A
SA
Seed Biosynthesis Research Unit, United States Department of Agriculture, Peoria, IL 61604.
Miernyk
J A
JA
Ohlrogge
J B
JB
D000213:Acyl Carrier Protein / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000494:pharmacology; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003065:Coenzyme A / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D015636:Magnesium Chloride; D010770:Phosphotransferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology; D017855:Transferases (Other Substituted Phosphate Groups)
D000213:Acyl Carrier Protein; D015636:Magnesium Chloride; D000244:Adenosine Diphosphate; D010770:Phosphotransferases; D017855:Transferases (Other Substituted Phosphate Groups); C021364:holo-(acyl-carrier-protein) synthase; D008274:Magnesium; D003065:Coenzyme A