eprintid: 6358 rev_number: 7 eprint_status: archive userid: 128 dir: disk0/00/00/63/58 datestamp: 2012-12-27 03:44:29 lastmod: 2012-12-27 03:44:29 status_changed: 2012-12-27 03:44:29 type: article metadata_visibility: show contact_email: Library-ICRISAT@CGIAR.ORG creators_name: Akbar S., MD. creators_name: Jayalakshmi, S K creators_name: Sharma, H C creators_name: Sreeramulu, K icrisatcreators_name: Akbar S., MD. icrisatcreators_name: Sharma, H C affiliation: Gulbarga University(Gulbarga) affiliation: ICRISAT(Patancheru) country: India title: Characterization of dihydrolipoamide dehydrogenase from the mitochondria of Helicoverpa armigera, a pest resistant to insecticides ispublished: pub subjects: s2.7 full_text_status: restricted keywords: arsenical compounds;dihydrolipomide dehydrogenase;Helicoverpa armigera;mitochondria note: Providing a junior research fellowship under the scheme “Research Fellowship in Science for Meritorious Students” (RFSMS). abstract: Dihydrolipoamide dehydrogenase (DHLDH) was isolated from the mitochondria of Helicoverpa armigera, a destructive pest which has developed resistance to commonly used insecticides. The flavoenzyme was purified 17.98-fold to homogeneity with an overall yield of 10.53% by employing ammonium sulfate precipitation, hydroxylapatite chromatography and CM-Sephadex chromatography. The purified enzyme exhibited the specific activity of 18.7 U/mg and was characterized as a dimer with a subunit mass of 66 kDa. The enzyme showed specificity for nicotinamide adenine dinucleotide – hydrogen (NADH) and lipoamide, as substrates, with Michaelis-Menten constants (Km) of 0.083 mmol/L and 0.4 mmol/L, respectively. The reduction reaction of lipoamide by the enzyme could be explained by ping-pong mechanism. The spectra of DHLDH showed the maximum absorbance at 420 nm, 455 nm and 475 nm. The enzyme activity was strongly inhibited by mercurial and arsenical compounds. The N-terminal sequence of Ha-DHLDH showed homology with those of mammalian and arthropod DHLDH. Since H. armigera has developed high levels of resistance to commonly used insecticides, biochemical properties of the metabolic enzymes such as DHLDH, could be helpful to develop insecticidal molecules for the control of H. armigera, with a different mode of action. date: 2011 date_type: published publication: Entomological Research volume: 41 number: 6 publisher: John Wiley & Sons, Inc. in association with the Entomological Society of Korea pagerange: 221-228 refereed: TRUE issn: 1748-5967 official_url: http://dx.doi.org/10.1111/j.1748-5967.2011.00346.x related_url_url: http://scholar.google.co.in/scholar?as_q=%22Characterization+of+dihydrolipoamide+dehydrogenase+from+the+mitochondria+of+Helicoverpa+armigera%2C+a+pest+resistant+to+insecticides%22&as_epq=&as_oq=&as_eq=&as_occt=title&as_sauthors=&as_publication=&as_ylo=&as related_url_type: pub funders: University of Agricultural Sciences, New Delhi, India citation: Akbar S., MD. and Jayalakshmi, S K and Sharma, H C and Sreeramulu, K (2011) Characterization of dihydrolipoamide dehydrogenase from the mitochondria of Helicoverpa armigera, a pest resistant to insecticides. Entomological Research, 41 (6). pp. 221-228. ISSN 1748-5967 document_url: http://oar.icrisat.org/6358/1/ER_41_221-228_2011.pdf