Identification and characterization of hydrolytic enzymes from the midgut of Sunn Pest of wheat (Eurygaster integriceps)

Ogur, E.
Öktem, Hüseyin Avni
To help in the development of Sunn Pest-resistant transgenic plants employing protease or alpha-amylase inhibitors, midgut hydrolytic enzymes of Sunn Pest (Eurygaster integriceps, Put.) (Heteroptera: Scutelleridae) were identified and characterized biochemically. We observed levels of very low proteolytic activity of trypsin (3 nmoles/min/mg), elastase (0.66 nmoles/min/mg) and leucine aminopeptidase-like (14.4 nmoles/min/mg) proteases, but no chymotrypsin and papain-like activity. Proteolytic activities were insensitive to inhibition by soybean trypsin inhibitor (SBTI) and aprotinin, but were inhibited to varying degrees (40-100%) by the synthetic protease inhibitors PMSF, TPCK, CdCl2 and CuCl2. Compared to proteolytic activity, significantly higher amylolytic activity (4.45 mmoles/min/mg) was observed. Alpha-amylase activity was found to be resistant to inhibition by bean and chickpea alpha-amylase inhibitors, and only slightly inhibited by wheat (36.9 +/- 1.8%) and maize (40.2 +/- 2.8) alpha-amylase inhibitors. Here, we report on the biochemical properties of digestive enzymes from Sunn Pest midgut, and their inhibition patterns by several synthetic and natural hydrolytic enzyme inhibitors.


Detection of physically interacting proteins with the CC and NB-ARC domains of a putative yellow rust resistance protein, Yr10, in wheat
Yildirim-Ersoy, Figen; Ridout, Christopher J.; Akkaya, Mahinur (Springer Science and Business Media LLC, 2011-08-01)
Gene-for-gene (GFG) resistance is a potent defense mechanism in plants, that is mediated by resistance (R) proteins. In GFG resistance, pathogen effector or avirulence (Avr) proteins are recognised by R-proteins which initiate a series of signal transduction events that lead to hypersensitive cell death. In cereals, many R-proteins are comprised of an N-terminal coiled-coiled (CC) domain, a Nucleotide Binding (NB) domain and a Leucine Rich Repeats (LRR) region associated with effector recognition. NB-LRR im...
Identification and characterization of hydrolytic enzymes from the midgut of the cotton bollworm, Helicoverpa armigera Hubner (Lepidoptera: Noctuidae)
Ozgur, Ebru; Yucel, Meral; Öktem, Hüseyin Avni (2009-01-01)
Midgut hydrolytic enzymes of Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) were identified and partially characterized. K-m, V-max, optimum pH, and specific activity were determined for proteolytic enzymes and alpha-amylases. All hydrolytic enzyme activity had an optimum pH value in the alkaline pH range. We observed major serine protease activity, together with minor cysteine-like activity, the former being significantly inhibited by soybean trypsin inhibitor (SBTI) and aprotinin. Moreover, differen...
Characterization of extracellular beta-lactamases from penicillin G-resistant cells of Streptococcus thermophilus
Chirica, LC; Güray, Nülüfer Tülün; Gültekin, Güzin Candan; Bozoglu, F (International Association for Food Protection, 1998-07-01)
In this study, biochemical properties of two extracellular beta-lactamases produced by penicillin-resistant Streptococcus thermophilus cells were investigated. Both beta-lactamases showed specificity for penicillins but not for cephaloridins. The p-lactamases exhibited different affinities for penicillin G. The one with the higher molecular weight (F1) had a K(m) value of 3.44 mu M and a V(max), value of 8.33, mu mol/min/mg of protein, whereas the beta-lactamase with the lower molecular weight (FII) had a K...
Detection of contaminated hazelnuts and ground red chili pepper flakes by multispectral imaging
Kalkan, H.; Beriat, P.; Yardimci, Y.; Pearson, T. C. (Elsevier BV, 2011-06-01)
Mycotoxins are the toxic metabolites of certain filamentous fungi and have been demonstrated to cause various health problems in humans, including immunosuppression and cancer. Among them, the aflatoxins have received greater attention because they are potent carcinogens and are responsible for many human deaths per annum, mostly in non-industrialized countries. Various regulatory agencies have enforced limits on the concentrations of these toxins in foods and feeds involved in international commerce. Hyper...
Identification of differentially expressed transcripts from leaves of the boron tolerant plant Gypsophila perfoliata L.
Unver, Turgay; Bozkurt, Osman; Akkaya, Mahinur (Springer Science and Business Media LLC, 2008-08-01)
Very recently some of the species of Gypsophila genus collected from the boron rich soils in Turkey were shown to be remarkably tolerant to high levels of boron. A limited amount of boron is necessary for the normal development of plants; however, a high level of boron in soil is generally toxic. Nevertheless, the adaptability of plant species allows them to withstand the presence of extreme amounts of metal ion by various strategies. This study is conducted on highly boron tolerant Gypsophila perfoliata L....
Citation Formats
E. Ogur, M. YÜCEL, and H. A. Öktem, “Identification and characterization of hydrolytic enzymes from the midgut of Sunn Pest of wheat (Eurygaster integriceps),” INTERNATIONAL JOURNAL OF PEST MANAGEMENT, pp. 359–364, 2009, Accessed: 00, 2020. [Online]. Available: