Linked Life Data

618849

Source:http://linkedlifedata.com/resource/pubmed/id/618849

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1978-2-18
pubmed:abstractText
The chain elongation of a wide variety of exogenous fatty acids and the subsequent incorporation of the chain elongation products into the total membrane lipids of Acholeplasma laidlawii B were systematically studied. Within each chemical class of fatty acids examined, the extent of chain elongation increased with increases in chain length, reached a maximum value, and then declined with further increases in chain length. Depending on chemical structure, exogenous fatty acids containing less than 6 to 9 carbon atoms or more than 15 to 18 carbon atoms were not substrates for the chain elongation system. The substrate specificity of this fatty acid elongation system was strikingly broad, and straight-chain, methyl isobranched, and methyl anteisobranched saturated fatty acids, as well as cis- and trans-monounsaturated, cis-cyclopropane, and cis-polyunsaturated fatty acids, underwent chain elongation in vivo. The extent of chain elongation and the average chain length of the primary elongation products correlated well with the physical properties (melting temperatures) of the exogenous fatty acid substrates. The specificity of fatty acid chain elongation in A. laidlawii B maintained the fluidity and physical state of the membrane lipids within a rather wide but definitely limited range. The fatty acid chain elongation system of this organism could be markedly influenced by the presence of a second exogenous fatty acid that was not itself a substrate for the chain elongation system but was incorporated directly into the membrane lipids. The presence of a relatively low-melting exogenous fatty acid increased both the extent of chain elongation and the average chain length of the elongation products generated, whereas the presence of a relatively high-melting fatty acid had the opposite effect. The extent of chain elongation and nature of the elongation products formed were not, however, dependent on the fluidity and physical state of the membrane lipids per se. The second exogenous fatty acid appeared instead to exert its characteristic effect by competing with the chain elongation substrate and elongation products for the stereospecific acylation of positions 1 and 2 of sn-glycerol-3-phosphate. The similar effects of alterations in environmental temperature, cholesterol content, and exposure to the antibiotic cerulenin on the fatty acid chain elongation and de novo biosynthetic activities suggested that the chain elongation system of this organism may be a component of the de novo biosynthetic system.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-1124935, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-4391501, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-4461849, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-4561339, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-4625866, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-4719142, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-4820352, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-5070656, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-5257955, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-5412665, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-6020566, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-900942, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-900943, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-914776, http://linkedlifedata.com/resource/pubmed/commentcorrection/618849-914777
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9193
pubmed:author
pubmed:issnType
Print
pubmed:volume
133
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
66-74
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1978
pubmed:articleTitle
Membrane lipid biosynthesis in Acholeplasma laidlawii b: elongation of medium- and long-chain exogenous fatty acids in growing cells.
pubmed:publicationType
Journal Article