Amino acid residues involved in substrate binding and catalysis in an insect digestive β-glycosidase

Marana, Sandro R.; Jacobs-­Lorena, Marcelo; Terra, Walter R.; Ferreira, Clélia

doi:10.1016/s0167-4838(00)00260-0

Cited by 58 publications

(64 citation statements)

References 30 publications

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“…Replacement with alanine removes most of the side chain contacts, which impairs the participation of the mutated residue as a central residue. The central residues R97, Y331 and E399 were not included in this analysis because they are located at the active site [18,21]. Mutant T245A was produced, although it was not soluble and was retained in inclusion bodies during bacterial expression.…”

Section: Resultsmentioning

confidence: 99%

“…In the present study, we report a systematic investigation of a set of planned mutants of the b-glycosidase GH1 Sfbgly (b-D-glucoside glucohydrolase; EC 3.2.1.21) from the fall armyworm Spodoptera frugiperda [18], an (a/b) 8 -fold enzyme that contains replacements of the main central residues and mutations of residues surrounding a main central residue. The Sfbgly mutants were characterized based on their thermal denaturation, which is an appropriate parameter for probing the participation of the central residues in protein stability.…”

Section: Introductionmentioning

confidence: 99%

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Protein thermal denaturation is modulated by central residues in the protein structure network

et al. 2016

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Network structural analysis, known as residue interaction networks or graphs (RIN or RIG, respectively) or protein structural networks or graphs (PSN or PSG, respectively), comprises a useful tool for detecting important residues for protein function, stability, folding and allostery. In RIN, the tertiary structure is represented by a network in which residues (nodes) are connected by interactions (edges). Such structural networks have consistently presented a few central residues that are important for shortening the pathways linking any two residues in a protein structure. To experimentally demonstrate that central residues effectively participate in protein properties, mutations were directed to seven central residues of the bglucosidase Sfbgly (b-D-glucoside glucohydrolase; EC 3.2.1.21). These mutations reduced the thermal stability of the enzyme, as evaluated by changes in transition temperature (T m ) and the denaturation rate at 45°C. Moreover, mutations directed to the vicinity of a central residue also caused significant decreases in the T m of Sfbgly and clearly increased the unfolding rate constant at 45°C. However, mutations at noncentral residues or at surrounding residues did not affect the thermal stability of Sfbgly. Therefore, the data reported in the present study suggest that the perturbation of the central residues reduced the stability of the native structure of Sfbgly. These results are in agreement with previous findings showing that networks are robust, whereas attacks on central nodes cause network failure. Finally, the present study demonstrates that central residues underlie the functional properties of proteins.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Protein thermal denaturation is modulated by central residues in the protein structure network

et al. 2016

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“…Digestive b-glycosidases from GH1 have been isolated from insect larvae that feed on plants [27,28]. Similarly, myrosinases have been isolated from specialist insects that feed on crucifers, such as the cabbage aphid, Brevicoryne brassicae [29].…”

Section: Insect B-glucosidases and Myrosinasesmentioning

confidence: 99%

β-Glucosidases

Cairns

Esen

2010

Cell. Mol. Life Sci.

469

214

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β-Glucosidases (3.2.1.21) are found in all domains of living organisms, where they play essential roles in the removal of nonreducing terminal glucosyl residues from saccharides and glycosides. β-Glucosidases function in glycolipid and exogenous glycoside metabolism in animals, defense, cell wall lignification, cell wall β-glucan turnover, phytohormone activation, and release of aromatic compounds in plants, and biomass conversion in microorganisms. These functions lead to many agricultural and industrial applications. β-Glucosidases have been classified into glycoside hydrolase (GH) families GH1, GH3, GH5, GH9, and GH30, based on their amino acid sequences, while other β-glucosidases remain to be classified. The GH1, GH5, and GH30 β-glucosidases fall in GH Clan A, which consists of proteins with (β/α)(8)-barrel structures. In contrast, the active site of GH3 enzymes comprises two domains, while GH9 enzymes have (α/α)(6) barrel structures. The mechanism by which GH1 enzymes recognize and hydrolyze substrates with different specificities remains an area of intense study.

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“…The aglycone binding region was also studied using alkyl b-glucosides as competitive inhibitors of the human citosolic b-glucosidase (41), Sfbglu (12) and Tenebrio molitor bglycosidases (39). These studies showed that the affinity between those b-glycosidases and the alkyl b-glucosides is directly proportional to the number of carbons (4 to 9) in the aglycone.…”

Section: Molecular Basis Of Aglycone Specificitymentioning

confidence: 99%

“…Indeed, subtle modifications in the glycone structure result in large changes in b-glycosidases activity. For instance, fucosides are hydrolyzed 40 times more quickly than galactosides by Spodoptera frugiperda b-glycosidase, although they differ just in what refers to hydroxyl 6, which is lacking in fucosides (12). bglycosidase activity is also affected by aglycone exchange.…”

Section: Introductionmentioning

confidence: 99%

Molecular basis of substrate specificity in family 1 glycoside hydrolases

Marana

2006

IUBMB Life (International Union of Biochemistry and Molecular B

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Summaryb-glycosidases are active upon a large range of substrates. Besides this, subtle changes in the substrate structure may result in large modifications on the b-glycosidase activity. The characterization of the molecular basis of b-glycosidases substrate preference may contribute to the comprehension of the enzymatic specificity, a fundamental property of biological systems. b-glycosidases specificity for the monosaccharide of the substrate nonreducing end (glycone) is controlled by a hydrogen bond network involving at least 5 active site amino acid residues and 4 substrate hydroxyls. From these residues, a glutamate, which interacts with hydroxyls 4 and 6, seems to be a key element in the determination of the preference for fucosides, glucosides and galactosides. Apart from this, interactions with the hydroxyl 2 are essential to the b-glycosidase activity. The active site residues forming these interactions and the pattern of the hydrogen bond network are conserved among all b-glycosidases. The region of the b-glycosidase active site that interacts with the moiety (called aglycone) which is bound to the glycone is formed by several subsites (1 to 3). However, the majority of the non-covalent interactions with the aglycone is concentrated in the first one, which presents a variable spatial structure and amino acid composition. This structural variability is in accordance with the high diversity of aglycones recognized by b-glycosidases. Hydrophobic interactions and hydrogen bonds are formed with the aglycone, but the manner in which they control the b-glycosidase specificity still remains to be determined.

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Amino acid residues involved in substrate binding and catalysis in an insect digestive β-glycosidase

Cited by 58 publications

References 30 publications

Protein thermal denaturation is modulated by central residues in the protein structure network

Protein thermal denaturation is modulated by central residues in the protein structure network

β-Glucosidases

Molecular basis of substrate specificity in family 1 glycoside hydrolases

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