• [email protected]
  • +971 507 888 742
Submit Manuscript
SciAlert
  • Home
  • Journals
  • Information
    • For Authors
    • For Referees
    • For Librarian
    • For Societies
  • Contact
  1. Journal of Applied Sciences
  2. Vol 13 (6), 2013
  3. 929-933
  • Online First
  • Current Issue
  • Previous Issues
  • More Information
    Aims and Scope Editorial Board Guide to Authors Article Processing Charges
    Submit a Manuscript

Journal of Applied Sciences

Year: 2013 | Volume: 13 | Issue: 6 | Page No.: 929-933
DOI: 10.3923/jas.2013.929.933

Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Article Trend



Total views 287

Search


Authors


R. Tarek Amin

Country: Egypt

E. Takwa Ellakwa

Country: Egypt

E. Doha Ellakwa

Country: Egypt

Keywords


  • Insecta
  • phenoloxidase
  • kinetic properties
  • Tuta absoluta
Research Article

Properties of Phenoloxidases from the Tomato Leafminer, Tuta absoluta (Meyrick)

R. Tarek Amin, E. Takwa Ellakwa and E. Doha Ellakwa
The kinetic properties of phenoloxidases system from the fourth larval instar of the tomato leafminer, Tuta absoluta (Meyrick) were studied to detect the optimum condition for phenoloxidases-catalyzed reaction. The results of phenoloxidases activity towards catechol at different pH values revealed that the optimum pH was 5.5. The phenoloxidases activity increased gradually from 15 to 35°C and began to decline that phenoloxidases lost 60.5% of their activity at 55°C. A period of only 2 min for the tomato leafminer phenoloxidases was found to fit well within the linear part of the enzyme activity curve. On the other hand, the oxidation was directly proportional to the substrate concentration up to 10-4 M, where the peak was reached. Using Lineweaver-Burk plot, it was found that Km (Michaelis constant) was 12.98 10-6 M, while Vmax (maximum velocity of the reaction) was 0.862 O.D. units/min/mg proteins. The relatively small Km value indicates that phenoloxidases can hydrolyze catechol efficiently, even at very low concentration. The significance of results and effect of organic solvents on phenoloxidases reaction were discussed. It could be concluded that 1 mL of the reaction mixture consists of 5 μg sample protein and 0.1 mM catechol in 0.1 M phosphate buffer (pH 5.5) at 25°C for 2 min, represents the optimum condition for T. absoluta phenoloxidases system activity.
PDF Fulltext XML References Citation

How to cite this article

R. Tarek Amin, E. Takwa Ellakwa and E. Doha Ellakwa, 2013. Properties of Phenoloxidases from the Tomato Leafminer, Tuta absoluta (Meyrick). Journal of Applied Sciences, 13: 929-933.

DOI: 10.3923/jas.2013.929.933

URL: https://scialert.net/abstract/?doi=jas.2013.929.933

Leave a Comment


Your email address will not be published. Required fields are marked *

Useful Links

  • Journals
  • For Authors
  • For Referees
  • For Librarian
  • For Socities

Contact Us

Office Number 1128,
Tamani Arts Building,
Business Bay,
Deira, Dubai, UAE

Phone: +971 507 888 742
Email: [email protected]

About Science Alert

Science Alert is a technology platform and service provider for scholarly publishers, helping them to publish and distribute their content online. We provide a range of services, including hosting, design, and digital marketing, as well as analytics and other tools to help publishers understand their audience and optimize their content. Science Alert works with a wide variety of publishers, including academic societies, universities, and commercial publishers.

Follow Us
© Copyright Science Alert. All Rights Reserved