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Spencer PW, Titus JS. The occurrence and nature of ornithine carbamoyltransferase in senescing apple leaf tissue. Plant Physiol. 1974;54(3):382-5doi: 10.1104/pp.54.3.382.
Spencer, P. W., & Titus, J. S. (1974). The occurrence and nature of ornithine carbamoyltransferase in senescing apple leaf tissue. Plant physiology, 54(3), 382-5. https://doi.org/10.1104/pp.54.3.382
Spencer, P W, and Titus, J S. "The occurrence and nature of ornithine carbamoyltransferase in senescing apple leaf tissue." Plant physiology vol. 54,3 (1974): 382-5. doi: https://doi.org/10.1104/pp.54.3.382
Spencer PW, Titus JS. The occurrence and nature of ornithine carbamoyltransferase in senescing apple leaf tissue. Plant Physiol. 1974 Sep;54(3):382-5. doi: 10.1104/pp.54.3.382. PMID: 16658894; PMCID: PMC367417.
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Plant Physiol. 1974 Sep;54(3):382-5. doi: 10.1104/pp.54.3.382.

The occurrence and nature of ornithine carbamoyltransferase in senescing apple leaf tissue.

Plant physiology

P W Spencer, J S Titus

Affiliations

  1. Department of Horticulture, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.

PMID: 16658894 PMCID: PMC367417 DOI: 10.1104/pp.54.3.382

Abstract

Ornithine carbamoyltransferase (EC 2.1.3.3) activity was detected in apple (Pyrus malus L.) leaf tissue from early June to November. Total activity remained relatively constant at 4.1 mumoles citrulline produced per hour per 10 cm(2) until mid-October when it sharply doubled. Following the first frost of the autumn, the enzyme lost about 80% of its former activity. The enzyme from apple leaf exhibited two pH optima, one at pH 8.6 and the other at pH 7.8, indicating the presence of isozymes or two forms of the enzyme. At pH 8.6, a partially-purified enzyme preparation had binding contrasts for its substrates of 6 mm for carbamyl-phosphate and 4.8 mm for ornithine. At pH 7.8, the Km for carbamyl-phosphate was 1.9 mm and the Km for ornithine was 1.22 mm.

References

  1. J Biol Chem. 1959 Jun;234(6):1452-5 - PubMed
  2. Plant Physiol. 1972 May;49(5):746-50 - PubMed
  3. J Biol Chem. 1973 Aug 10;248(15):5403-8 - PubMed
  4. J Biol Chem. 1962 Feb;237:459-68 - PubMed
  5. Plant Physiol. 1973 Aug;52(2):151-5 - PubMed
  6. Plant Physiol. 1972 May;49(5):808-12 - PubMed

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