|
rdf:type |
|
|
lifeskim:mentions |
|
|
pubmed:issue |
2
|
|
pubmed:dateCreated |
1977-11-30
|
|
pubmed:abstractText |
1. The route of l-threonine degradation was studied in four strains of the genus Pseudomonas able to grow on the amino acid and selected because of their high l-threonine aldolase activity. Growth and manometric results were consistent with the cleavage of l-threonine to acetaldehyde+glycine and their metabolism via acetate and serine respectively. 2. l-Threonine aldolases in these bacteria exhibited pH optima in the range 8.0-8.7 and K(m) values for the substrate of 5-10mm. Extracts exhibited comparable allo-l-threonine aldolase activities, K(m) values for this substrate being 14.5-38.5mm depending on the bacterium. Both activities were essentially constitutive. Similar activity ratios in extracts, independent of growth conditions, suggested a single enzyme. The isolate Pseudomonas D2 (N.C.I.B. 11097) represents the best source of the enzyme known. 3. Extracts of all the l-threonine-grown pseudomonads also possessed a CoA-independent aldehyde dehydrogenase, the synthesis of which was induced, and a reversible alcohol dehydrogenase. The high acetaldehyde reductase activity of most extracts possibly resulted in the underestimation of acetaldehyde dehydrogenase. 4. l-Serine dehydratase formation was induced by growth on l-threonine or acetate+glycine. Constitutively synthesized l-serine hydroxymethyltransferase was detected in extracts of Pseudomonas strains D2 and F10. The enzyme could not be detected in strains A1 and N3, probably because of a highly active ;formaldehyde-utilizing' system. 5. Ion-exchange and molecular exclusion chromatography supported other evidence that l-threonine aldolase and allo-l-threonine aldolase activities were catalysed by the same enzyme but that l-serine hydroxymethyltransferase was distinct and different. These results contrast with the specificities of some analogous enzymes of mammalian origin.
|
|
pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-13753188,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-14053263,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-14320497,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-14342490,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-16591426,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-16743051,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-4482717,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-4628671,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-4686921,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-4723219,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-4976434,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5017702,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5017703,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5353532,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5414101,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5419750,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5419751,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5438301,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5637708,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5729603,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5729604,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5821726,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-5862401,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-7548,
http://linkedlifedata.com/resource/pubmed/commentcorrection/911318-942418
|
|
pubmed:language |
eng
|
|
pubmed:journal |
|
|
pubmed:citationSubset |
IM
|
|
pubmed:chemical |
|
|
pubmed:status |
MEDLINE
|
|
pubmed:month |
Aug
|
|
pubmed:issn |
0264-6021
|
|
pubmed:author |
|
|
pubmed:issnType |
Print
|
|
pubmed:day |
15
|
|
pubmed:volume |
166
|
|
pubmed:owner |
NLM
|
|
pubmed:authorsComplete |
Y
|
|
pubmed:pagination |
209-16
|
|
pubmed:dateRevised |
2010-9-3
|
|
pubmed:meshHeading |
|
|
pubmed:year |
1977
|
|
pubmed:articleTitle |
Bacterial catabolism of threonine. Threonine degradation initiated by L-threonine acetaldehyde-lyase (aldolase) in species of Pseudomonas.
|
|
pubmed:publicationType |
Journal Article
|
