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Fatty acid synthesis by spinach chloroplasts, 2. The path from PGA to fatty acids

Journal Article:

Abstract

By incorporation of /sup 3/H/sub 2/O into the fatty acid chain in the presence of unlabelled precursor, we showed that fatty acids are synthesized from PGA, PEP and pyruvate by intact spinach chloroplasts in the light. /sup 13/C-tracer experiments confirmed that 1-C of pyruvate is decarboxylated and 2-C is incorporated into fatty acids by the chloroplasts. The patterns of fatty acids synthesized from PGA and pyruvate were the same as that from acetate. The highest rate of fatty acid synthesis was reached at the physiological concentration of PGA (3 mM) and pyruvate (1 mM). These results indicate the operation of the following path in the chloroplasts in light: PGA..-->..PEP..-->..pyruvate..-->..acetylCoA..-->..fatty acids. Since citrate and OAA were much less active and malate and glyoxylate were inert as precursors for fatty acid synthesis, PEP or pyruvate carboxylation, citrate lyase reaction and malate synthetase reaction are not involved in the formation of acetylCoA and fatty acids. Since pyruvate was much more effective as a substrate for fatty acid synthesis than lactate, acetaldehyde or acetate, direct decarboxylation path is considered to be the primary path from pyruvate to acetylCoA. The insignificant effect of chloroplast-washing on fatty acid synthesis from PGA and pyruvate indicates that the  More>>
Authors:
Yamada, Mitsuhiro; Nakamura, Yasunori [1] 
  1. Tokyo Univ. (Japan). Coll. of General Education
Publication Date:
Feb 01, 1975
Product Type:
Journal Article
Reference Number:
EDB-76-043633
Resource Relation:
Journal Name: Plant Cell Physiol. (Kyoto); (Japan); Journal Volume: 16:1
Subject:
59 BASIC BIOLOGICAL SCIENCES; CARBOXYLIC ACIDS; BIOSYNTHESIS; CARBON 13; CHLOROPLASTS; LABELLED COMPOUNDS; LEAVES; METABOLISM; SPINACH; TRACER TECHNIQUES; TRITIUM COMPOUNDS; VISIBLE RADIATION; CARBON ISOTOPES; CELL CONSTITUENTS; ELECTROMAGNETIC RADIATION; EVEN-ODD NUCLEI; FOOD; ISOTOPE APPLICATIONS; ISOTOPES; LIGHT NUCLEI; NUCLEI; ORGANIC ACIDS; ORGANIC COMPOUNDS; RADIATIONS; STABLE ISOTOPES; SYNTHESIS; VEGETABLES; 550201* - Biochemistry- Tracer Techniques; 551001 - Physiological Systems- Tracer Techniques
OSTI ID:
7286180
Country of Origin:
Japan
Language:
English
Other Identifying Numbers:
Journal ID: CODEN: PLCPB
Submitting Site:
INIS
Size:
Pages: 151-162
Announcement Date:

Journal Article:

Citation Formats

Yamada, Mitsuhiro, and Nakamura, Yasunori. Fatty acid synthesis by spinach chloroplasts, 2. The path from PGA to fatty acids. Japan: N. p., 1975. Web.
Yamada, Mitsuhiro, & Nakamura, Yasunori. Fatty acid synthesis by spinach chloroplasts, 2. The path from PGA to fatty acids. Japan.
Yamada, Mitsuhiro, and Nakamura, Yasunori. 1975. "Fatty acid synthesis by spinach chloroplasts, 2. The path from PGA to fatty acids." Japan.
@misc{etde_7286180,
title = {Fatty acid synthesis by spinach chloroplasts, 2. The path from PGA to fatty acids}
author = {Yamada, Mitsuhiro, and Nakamura, Yasunori}
abstractNote = {By incorporation of /sup 3/H/sub 2/O into the fatty acid chain in the presence of unlabelled precursor, we showed that fatty acids are synthesized from PGA, PEP and pyruvate by intact spinach chloroplasts in the light. /sup 13/C-tracer experiments confirmed that 1-C of pyruvate is decarboxylated and 2-C is incorporated into fatty acids by the chloroplasts. The patterns of fatty acids synthesized from PGA and pyruvate were the same as that from acetate. The highest rate of fatty acid synthesis was reached at the physiological concentration of PGA (3 mM) and pyruvate (1 mM). These results indicate the operation of the following path in the chloroplasts in light: PGA..-->..PEP..-->..pyruvate..-->..acetylCoA..-->..fatty acids. Since citrate and OAA were much less active and malate and glyoxylate were inert as precursors for fatty acid synthesis, PEP or pyruvate carboxylation, citrate lyase reaction and malate synthetase reaction are not involved in the formation of acetylCoA and fatty acids. Since pyruvate was much more effective as a substrate for fatty acid synthesis than lactate, acetaldehyde or acetate, direct decarboxylation path is considered to be the primary path from pyruvate to acetylCoA. The insignificant effect of chloroplast-washing on fatty acid synthesis from PGA and pyruvate indicates that the glycolytic path from PGA to pyruvate is associated with the chloroplasts. Since pyruvate was more effectively incorporated into fatty acids than acetylCoA, it is unlikely that pyruvate decarboxylation to acetylCoA is due to mitochondria contaminating the chloroplast preparation. On the basis of measurements of /sup 3/H/sub 2/O incorporation in the light and dark, the activity of fatty acid synthesis in spincah leaves appears to be shared by the activities in chloroplasts (87%) and other organelles (13%).}
journal = {Plant Cell Physiol. (Kyoto); (Japan)}
volume = {16:1}
journal type = {AC}
place = {Japan}
year = {1975}
month = {Feb}
}