Kinetic and regulatory properties of pyruvate kinase isozymes from flight muscle and fat body of the cockroach,Periplaneta americana

Storey, Kenneth B.

doi:10.1007/bf00687476

Cited by 12 publications

(2 citation statements)

References 23 publications

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“…In addition, several studies have demonstrated that PK activity is regulated by a number of amino acids that can either enhance or inhibit its activity. In many organisms such as humans, rats, chickens, crickets and cockroaches, alanine and phenylalanine are allosteric inhibitors of PK (Hoffmann, 1975; Ibsen and Marles, 1976; Imamura and Tanaka, 1982; Llorente et al, 1970; Morgan et al, 2013; Storey, 1985; Van Berkel et al, 1973; Yuan et al, 2018). In Trypanosoma brucei, the enzyme is stimulated by phenylalanine, whereas alanine, glutamic acid, proline, and serine have no effect on the PK activity (Callens et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

“…The regulation of PK is important for controlling glycolytic flux, which sequentially impacts the levels of intracellular metabolite pools (Mattevi et al, 1996). In insects, PK from the flight muscles of American cockroaches ( Periplaneta americana ) and desert locusts ( Schistocerca gregaria ) displayed Michaelis-Menten kinetics, whereas the enzyme from the fat body of the same organisms showed allosteric sigmoidal properties (Bailey and Walker, 1969; Storey, 1985). In mealworm beetles ( Tenebrio molitor ), the change in PK kinetic properties was observed during physiological alteration, such as injury, starvation, and insecticide or acetone injection (Papadopoulos, 2005).…”

Section: Introductionmentioning

confidence: 99%

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Distinctive regulatory properties of pyruvate kinase 1 from Aedes aegypti mosquitoes

Petchampai

Murillo-Solano

Isoe

et al. 2019

Insect Biochemistry and Molecular Biology

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Female Aedes aegypti mosquitoes are vectors of arboviruses that cause diseases of public health significance. The discovery of new metabolic targets is crucial for improving mosquito control strategies. We recently demonstrated that glucose oxidation supports ammonia detoxification in Aedes aegypti. Pyruvate kinase (PK, EC 2.7.1.40) catalyzes the last step of the glycolytic pathway. In most organisms, one or more allosteric effectors control PK activity. However, the kinetic properties and structure of PK in mosquitoes have not been previously reported. In this study, two alternatively spliced mRNA variants (AaPK1 and AaPK2) that code for PKs were identified in the A. aegypti genome. The AaPK1 mRNA variant, which encodes a 529 amino acid protein with an estimated molecular weight of ~57 kDa, was cloned. The protein was expressed in Escherichia coli and purified. The AaPK1 kinetic properties were identified. The recombinant protein was also crystallized and its 3D structure determined. We found that alanine, glutamine, proline, serine and fructose-1-phosphate displayed a classic allosteric activation on AaPK1. Ribulose-5-phosphate acted as an allosteric inhibitor of AaPK1 but its inhibitory effect was reversed by alanine, glutamine, proline and serine. Additionally, the allosteric activation of AaPK1 by amino acids was weakened by fructose-1,6-bisphosphate, whereas the allosteric activation of AaPK1 by alanine and serine was diminished by glucose-6-phosphate. The AaPK1 structure shows the presence of fructose-1,6-bisphosphate in the allosteric site. Together, our results reveal that specific amino acids and phosphorylated sugars tightly regulate conformational dynamics and catalytic changes of AaPK1. The distinctive AaPK1 allosteric properties support a complex role for this enzyme within mosquito metabolism.

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