Substrate mimicry in the active center of a mammalian α amylase: structural analysis of an enzyme–inhibitor complex

Bompard-Gilles, C.; Rousseau, P.; Rougé, Pierre; Payan, F.

doi:10.1016/s0969-2126(96)00151-7

Cited by 134 publications

(136 citation statements)

References 31 publications

(86 reference statements)

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“…It has been suggested that peptidecarbohydrate mimicry originates in mimicry of specific chemical groups of the carbohydrate by chemical groups of the peptide (structural mimicry) (27)(28)(29). Some structural mimicry has been observed in the complexes of several mimetic proteins, e.g., in the complex of a camel heavy-chain antibody against lysozyme, where parts of some residues of the antibody mimic parts of the sugar substrate of lysozyme (30), and in the complex of porcine pancreatic ␣-amylase with the proteinaceous inhibitor, where several specific hydrogen-bonding and hydrophobic interactions with the carbohydrate substrate are mimicked by the inhibitor (31). The concept of structural mimicry is also closely related to the immune network theory of Jerne and the concept of antiidiotypic antibodies (32).…”

Section: Resultsmentioning

confidence: 99%

Structural basis of peptide–carbohydrate mimicry in an antibody-combining site

Vyas

Chervenak

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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Section: Resultsmentioning

confidence: 99%

Structural basis of peptide–carbohydrate mimicry in an antibody-combining site

Vyas

Chervenak

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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“…Structures of several u-amylases (Larson et al, 1994;Mizuno et al, 1993;Tao et al, 1989),/3-amylases (Cheong et al, 1995: Mikami et al, 1994, glucoamylase (Aleshin et al, 1992(Aleshin et al, , 1996 and complexes of these enzymes with inhibitors (Aleshin et aL, 1994;Bompard-gilles et al, 1996;Mikami et al, 1993: Stoffer et al, 1995 have provided valuable insights into their enzymatic mechanisms. However, there is no threedimensional structure of any enzyme cleaving the u-l,6-glycosidic linkage (MacGregor, 1993).…”

Section: Introductionmentioning

confidence: 99%

Preliminary X-ray crystallographic analysis of a novel maltogenic amylase from Bacillus stearothermophilus ET1

Cho

Cha

Park

et al. 1998

Acta Crystallogr D Biol Cryst

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A novel maltogenic amylase from Bacillus stearothermophilus ETI, which has a dual activity of u-l,4-and a-l,6-glycosidic bond cleavages and u-l,6-glycosidic bond formation, was crystallized by using the hanging-drop vapor-diffusion method. The best crystals were obtained by employing a high concentration of protein (56mgml '1) and a precipitant containing 22% glycerol, 1.6 M ammonium sulfate in 0.1 M Tris-HCI (pH 8.5). Native diffraction data to 2.66 A resolution have been obtained from crystals flash-frozen at 110 K. The crystals belong to the space group P2~212~ with unit-cell dimensions of a = 77.62, b = 121.23, c = 244.29 A, and contain three or four protomers per asymmetric unit. Structure determination by multiple isomorphous replacement is in progress.

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“…Since the patterns of inhibition of M2-4 were identical to that of M1, these other mutants were not studied further. The structure of PPA in complex with α-AI1, PDB code 1DHK (Bompard-Gilles et al, 1996) was used to construct the PPA-α-AI2 and PPA-M1 model complexes while the structure of TMA in complex with α-AI1, PDB code 1VIW (Nahoum et al, 1999) was used for modeling ZSA-α-AI2 and ZSA-M1. Alignments were adjusted so that insertions and deletions in the model proteins relative to the templates could be smoothly accommodated.…”

Section: Methodsmentioning

confidence: 99%

Mutants of common bean alpha-amylase inhibitor-2 as an approach to investigate binding specificity to alpha-amylases

Silva

Mello

Coutinho

et al. 2004

Pesq. agropec. bras.

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-Despite the presence of a family of defense proteins, Phaseolus vulgaris can be attacked by bruchid insects resulting in serious damage to stored grains. The two distinct active forms of α-amylase inhibitors, α-AI1 and α-AI2, in P. vulgaris show different specificity toward α-amylases. Zabrotes subfasciatus α-amylase is inhibited by α-AI2 but not by α-AI1. In contrast, porcine α-amylase is inhibited by α-AI1 but not by α-AI2. The objective of this work was to understand the molecular basis of the specificity of two inhibitors in P. vulgaris (α-AI1 and α-AI2) in relation to α-amylases. Mutants of α-AI2 were made and expressed in tobacco plants. The results showed that all the α-AI2 mutant inhibitors lost their activity against the insect α-amylases but none exhibited activity toward the mammalian α-amylase. The replacement of His33 of α-AI2 with the α-AI1-like sequence Ser-Tyr-Asn abolished inhibition of Z. subfasciatus α-amylase. From structural modeling, the conclusion is that the size and complexity of the amylase-inhibitor interface explain why mutation of the N-terminal loop and resultant abolition of Z. subfasciatus α-amylase inhibition are not accompanied by gain of inhibitory activity against porcine α-amylase.Index terms: Phaseolus vulgaris, α-amylase inhibitors, inhibitor specificity, site directed mutagenesis, structural modeling. Mutantes do inibidor-2 de alfa-amilase do feijão-comum para investigação da especificidade de ligação a alfa-amilasesResumo -Apesar de possuir uma família de proteínas de defesa, o feijão-comum (Phaseolus vulgaris L.) pode ser atacado por insetos bruquídeos causando sérios danos aos grãos armazenados. O P. vulgaris possui duas formas ativas de inibidores de α-amilases, denominadas α-AI1 e α-AI2, que apresentam diferentes especificidades em relação às α-amilases. A α-amilase de Zabrotes subfasciatus é inibida por α-AI2 mas não por α-AI1. Em contraste, a α-amilase pancreática de porco é inibida por α-AI1 mas não é por α-AI2. O objetivo deste trabalho foi entender as bases moleculares da especificidade desses inibidores em relação às α-amilases. Para tanto, foram construídos mutantes do α-AI2, os quais foram expressados em plantas de fumo. Todos os inibidores mutantes deixaram de inibir a α-amilase de inseto sem, contudo, passar a exibir atividade contra a α-amilase de mamífero. Os modelos estruturais explicam por que a substituição de His33 do α-AI2 pela seqüência correspondente do α-AI1 (Ser-Tyr-Asn) aboliu a inibição da α-amilase de Z. subfasciatus. Dos estudos de modelagem molecular pode-se concluir que o tamanho e a complexidade da interface α-amilase-inibidor explicam por que a mutação da alça N-terminal e a quebra da atividade inibitória para α-amilase de Z. subfasciatus não levam ao ganho de atividade inibitória do mutante em relação à α-amilase de porco.Termos para indexação: Phaseolus vulgaris, inibidores de α-amilases, especificidade de interação, mutagênese sítio-dirigida, modelagem molecular.

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Substrate mimicry in the active center of a mammalian α amylase: structural analysis of an enzyme–inhibitor complex

Cited by 134 publications

References 31 publications

Structural basis of peptide–carbohydrate mimicry in an antibody-combining site

Structural basis of peptide–carbohydrate mimicry in an antibody-combining site

Preliminary X-ray crystallographic analysis of a novel maltogenic amylase from Bacillus stearothermophilus ET1

Mutants of common bean alpha-amylase inhibitor-2 as an approach to investigate binding specificity to alpha-amylases

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