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

Amin, Radjali; Ellakwa, E. Takwa; Ellakwa, E. Doha

doi:10.3923/jas.2013.929.933

Cited by 4 publications

(7 citation statements)

References 6 publications

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“…On the other hand, the optimum temperature of PO in the present work was 40°C which is similar to other insects having PO maximum activity equal or closely related to our findings as in P. rapae (Xue et al, 2006) and H. cunea (Sharifi and Ghadamyari, 2014). In general, the optimum temperature of PO activity ranged PO between 35 and 45°C in most studied insects (Ishaaya, 1970;Lockey and Orth 1992;Zibaee et al, 2011;Amin et al, 2013;Gholami et al, 2013 andTaleh et al, 2013). Amin et al, (2013) concluded that the activity of PO in T. absoluta larvae increased gradually after 15°C till reaching the optimum temperature which was 35°C but at 40 and 50°C the enzyme lost its activity by 11.36 and 37.3% respectively, while at 55°C, lost most of its activity by 60.5%.…”

Section: Michaelis-menten Kinetics Of Phenoloxidase Systemsupporting

confidence: 90%

“…In general, the optimum temperature of PO activity ranged PO between 35 and 45°C in most studied insects (Ishaaya, 1970;Lockey and Orth 1992;Zibaee et al, 2011;Amin et al, 2013;Gholami et al, 2013 andTaleh et al, 2013). Amin et al, (2013) concluded that the activity of PO in T. absoluta larvae increased gradually after 15°C till reaching the optimum temperature which was 35°C but at 40 and 50°C the enzyme lost its activity by 11.36 and 37.3% respectively, while at 55°C, lost most of its activity by 60.5%. Similarly, in musca domestica, PO activity was stable between 0 and 40°C but was unstable in higher than 50 °C and at 60°C PO lost 80% of its activity (Takuji et al, 1986).…”

Section: Michaelis-menten Kinetics Of Phenoloxidase Systemmentioning

confidence: 98%

“…Phenoloxidase activity was determined according to Ishaaya (1971) with modifications made by Amin et al, (2013). The reaction mixture consisted of 0.5 mL phosphate buffer (0.1 M), 200 µl of Catechol solutions as substrate concentration and reaction temperature was determined to detect the optimum conditions of the reactions.…”

Section: Kinetic Properties Of Phenoloxidase Systemmentioning

confidence: 99%

“…Similar findings were obtained in different insects as pieris rapae (Xue et al, 2006), Hyphantria cunea (Sharifi and Ghadamyari, 2014) while the optimum pH was slightly acidic in other insects being 6.5 Halophora cecropia (Anderson et. al., 1998) and in Sarcophaga bullata (Wang et al, 2004;and Feng et al, 2008), 6.2 in Parasarcophaga surcoufi (Ayaad et al, 2001), 6 in Helicoverpa armigera (Taleh et al, 2013), Bombyx mori (Ashida, 1971) as well as Eurygaster integriceps (Zibaee et al, 2011), 5.5 in Tuta absoluta (Amin et al, 2013). On the other hand, the optimum PH of PO was alkaline in other insects and reached 8.0 in Lymantria dispar (Dunphy 1991) and Ospheranteria coerulescens (Gholami et al, 2013) while in Heliothis virescens was 9 (Lockey and Orth 1992).…”

Section: Michaelis-menten Kinetics Of Phenoloxidase Systemmentioning

confidence: 99%

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Characterization of Phenoloxidase in The Red Palm Weevil; Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) (Olivier) Using Catechol Substrate

Amin

Fahmy²

2022

Egyptian Academic Journal of Biological Sciences. C, Physiology

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Phenoloxidases (EC.1.14.18.1) are implicated in the immunity of insects toward microorganisms, so oxidative enzymes such as phenoloxidases (PO) from the 7 th instar larvae of the red palm weevil; Rhynchophorus ferrugineus (Oliv.) was partially isolated to characterize its activity using catechol as a substrate. The mitochondrial fraction of larval homogenate was used as enzyme source for partial kinetic studies.Enzyme catalysis was directly proportional to enzyme crude protein conc. up to 200 ug contained in 1 ml of the reaction mixture. Michaelis-Menten kinetics of PO activity was evaluated by constructing Lineweaver Burk double reciprocal plot. Michaelis constant (Km) was, 3.45 X10 -4 M and maximum velocity (V max) of PO reaction was 344.8 O.D.min -1 mg protein -1 . Effect of pH, temperature and substrate concentration on enzyme reaction was tested. Generally, each variable was chosen while other conditions were at optimum found primarily. Reaction rate was optimal at 10 -1 N catechol, neutral medium (pH 7) and 40 C. PO kept its most activity when incubated at 60 C for 15 min before reaction initiation. Phenoloxidases efficiently catalyze catechol. Results in the present study may probably offer a fundamental anchor for future alternative strategies in controlling R. ferrugineus via obstructing its innate defence mechanisms.

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Section: Michaelis-menten Kinetics Of Phenoloxidase Systemsupporting

confidence: 90%

Section: Michaelis-menten Kinetics Of Phenoloxidase Systemmentioning

confidence: 98%

Section: Kinetic Properties Of Phenoloxidase Systemmentioning

confidence: 99%

Section: Michaelis-menten Kinetics Of Phenoloxidase Systemmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of Phenoloxidase in The Red Palm Weevil; Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) (Olivier) Using Catechol Substrate

Amin

Fahmy²

2022

Egyptian Academic Journal of Biological Sciences. C, Physiology

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“…This is might largely a result of the difficulty of collecting haemolymph from it, owing to its small size, and the tendency of haemolymph to clot within few seconds after puncture of the body wall preventing blood flow. Amin and Ellakwa (2013) studied the kinetic properties of phenoloxidases from the tomato leafminer.…”

Section: Introductionmentioning

confidence: 99%

Haemolymph of Tuta absoluta: Collection procedure and chemical characteristics

Amin

Mohamady

2013

Egyptian Academic Journal of Biological Sciences. C, Physiology

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A technique used to collect haemolymph of the tomato leafminer; Tuta absoluta (Lepidoptera) fourth larval instar was described. It depends on centrifugation of the larvae at a given speed. This technique has the advantage that it enables collecting blood from T. absoluta larvae whereas manual expression of blood from the cut ends of prologs is impossible. Approximatry 11 µl of haemolymph from 8-10 larvae were collected after centrifugation for 10 min at 1500 r.p.m.. The chemical characteristics of haemolymph plasma collected were studied. The haemolymph of the tomato leafminer contains 29.27, 390, 79, 440, 62.5 and 137.5 µg / ml of chloride, phosphorus, calcium, magnesium, sodium and potassium, respectively. Na: k ratio was 0.45, indicating the presence of low sodium index as an advanced feature like other Lepidopterans. The measured high magnesium content, and alkaline pH (=7.3) might be due to T. absoluta food habit as a phytophagous insect. In general, the main characteristics of the tomato lefminer are more or less similar to that of other species of Lepidoptera. The centrifugation technique is an efficient method to collect blood from small insects, but the optimal velocity of centrifugation must be detected for each species.

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Study on the inhibition kinetics parameters of esterases enzymes from the red palm Weevil Larvae

Ellakwa

Amin

2022

Ecological Genetics and Genomics

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

Cited by 4 publications

References 6 publications

Characterization of Phenoloxidase in The Red Palm Weevil; Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) (Olivier) Using Catechol Substrate

Characterization of Phenoloxidase in The Red Palm Weevil; Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) (Olivier) Using Catechol Substrate

Haemolymph of Tuta absoluta: Collection procedure and chemical characteristics

Study on the inhibition kinetics parameters of esterases enzymes from the red palm Weevil Larvae

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