Crystal Structure of Glucose-6-Phosphate Isomerase from Thermus thermophilus HB8 Showing a Snapshot of Active Dimeric State

Yamamoto, H.; Miwa, Hiroshi; Kunishima, N.

doi:10.1016/j.jmb.2008.07.041

Cited by 11 publications

(8 citation statements)

References 69 publications

(59 reference statements)

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“…It has been reported that most mammalian GPIs are homodimers that are composed of two identical subunits intracellularly, while they perform AMF and neurokine functions extracellularly as a monomer , . Our present result is different from the GPI from marine fish white croaker, which is a 55 kDa monomer , suggesting that GPIs are species-dependent.…”

Section: Discussioncontrasting

confidence: 85%

Glucose-6-phosphate Isomerase Is an Endogenous Inhibitor to Myofibril-Bound Serine Proteinase of Crucian Carp (Carassius auratus)

Sun

Zhou

et al. 2009

J. Agric. Food Chem.

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Glucose-6-phosphate isomerase (GPI) was purified to homogeneity from the skeletal muscle of crucian carp ( Carassius auratus ) by ammonium sulfate fractionation, column chromatographies of Q-Sepharose, SP-Sepharose, and Superdex 200 with a yield of 8.0%, and purification folds of 468. The molecular mass of GPI was 120 kDa as estimated by gel filtration, while on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two subunits (55 and 65 kDa) were identified, suggesting that it is a heterodimer. Interestingly, GPI revealed specific inhibitory activity toward a myofibril-bound serine proteinase (MBSP) from crucian carp, while no inhibitory activity was identified toward other serine proteinases, such as white croaker MBSP and crucian carp trypsin. Kinetic analysis showed that GPI is a competitive inhibitor toward MBSP, and the K(i) was 0.32 microM. Our present results indicated that the multifunctional protein GPI is an endogenous inhibitor to MBSP and may play a significant role in the regulation of muscular protein metabolism in vivo.

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Section: Discussioncontrasting

confidence: 85%

Glucose-6-phosphate Isomerase Is an Endogenous Inhibitor to Myofibril-Bound Serine Proteinase of Crucian Carp (Carassius auratus)

Sun

Zhou

et al. 2009

J. Agric. Food Chem.

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“…The crystal structure of PGI from the mouse phosphoglucose isomerase at 1.6 Å has been determined, which core fold of protomer and the interprotomer spatial arrangement of the dimer are similar to those of already reported crystal structures of other PGIs. [28,29] The active site involved in isomerization comprises highly conserved residues, including glutamic acid, histidine, lysine and arginine residues. In the enzyme catalyzed isomerization of glucose into fructose, several steps are involved as follows: (i) ring opening of glucose; (ii) formation of a cis-enediol intermediate by abstracting proton on C2 of glucose; (iii) transfer of proton; (iv) ring closure of chain fructose.…”

Section: Introductionmentioning

confidence: 99%

Highly Selective Isomerization of Glucose into Fructose Catalyzed by a Mimic Glucose Isomerase

Zhang

Meng

et al. 2019

ChemCatChem

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An amphoteric phenolic compound with carboxyl and amino functional groups was synthesized and used as mimic glucose isomerase to catalyze the isomerization of glucose into fructose. The mimic enzyme displayed excellent catalytic activity for isomerization of glucose to fructose under mild conditions. The yield of fructose and selectivity of fructose could reach 33.0 % and 93.5 % after reacting 4 h, respectively, at pH 8.5 and 80°C. The catalysis reaction rate constant k cat and Michaelis constants K mG , K mF were calculated. The activation energy of glucose to fructose was evaluated as 65.9 kJ mol À 1 . The possible catalysis reaction mechanism was proposed. The acid-base groups on the catalyst play an important role in proton extraction and transfer, as well as in the rotation of local carbon chain, which leads to the highly selective isomerization of glucose into fructose under mild conditions.

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“…However, the T. thermophilus HB8 PGI exists in solution as a dynamic equilibrium between monomer and dimer and, royalsocietypublishing.org/journal/rsob Open Biol. 11: 210098 owing to the high structural similarity, BbPGI may also exist in a similar equilibrium state [15].…”

Section: Overall Structure Of Bbpgimentioning

confidence: 99%

Bdellovibrio bacteriovorus phosphoglucose isomerase structures reveal novel rigidity in the active site of a selected subset of enzymes upon substrate binding

2021

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Glycolysis and gluconeogenesis are central pathways of metabolism across all domains of life. A prominent enzyme in these pathways is phosphoglucose isomerase (PGI), which mediates the interconversion of glucose-6-phosphate and fructose-6-phosphate. The predatory bacterium Bdellovibrio bacteriovorus leads a complex life cycle, switching between intraperiplasmic replicative and extracellular ‘hunter’ attack-phase stages. Passage through this complex life cycle involves different metabolic states. Here we present the unliganded and substrate-bound structures of the B. bacteriovorus PGI, solved to 1.74 Å and 1.67 Å, respectively. These structures reveal that an induced-fit conformational change within the active site is not a prerequisite for the binding of substrates in some PGIs. Crucially, we suggest a phenylalanine residue, conserved across most PGI enzymes but substituted for glycine in B. bacteriovorus and other select organisms, is central to the induced-fit mode of substrate recognition for PGIs. This enzyme also represents the smallest conventional PGI characterized to date and probably represents the minimal requirements for a functional PGI.

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Crystal Structure of Glucose-6-Phosphate Isomerase from Thermus thermophilus HB8 Showing a Snapshot of Active Dimeric State

Cited by 11 publications

References 69 publications

Glucose-6-phosphate Isomerase Is an Endogenous Inhibitor to Myofibril-Bound Serine Proteinase of Crucian Carp (Carassius auratus)

Glucose-6-phosphate Isomerase Is an Endogenous Inhibitor to Myofibril-Bound Serine Proteinase of Crucian Carp (Carassius auratus)

Highly Selective Isomerization of Glucose into Fructose Catalyzed by a Mimic Glucose Isomerase

Bdellovibrio bacteriovorus phosphoglucose isomerase structures reveal novel rigidity in the active site of a selected subset of enzymes upon substrate binding

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