Crystal structure of a lysozyme-tetrasaccharide lactone complex

Ford, L.O.; Johnson, L.N.; Machin, P.; Phillips, David; Tjian, Robert

doi:10.1016/0022-2836(74)90487-2

Cited by 168 publications

(87 citation statements)

References 32 publications

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“…These values are of a similar magnitude to those of amino-acid residues involving the NAG2 binding. The same tendency has been observed in the HEL complexes with trisaccharides (Ford et al, 1974;Strynadka & James, 1991;Cheetham, Artymiuk & Phillips, 1992). However, the temperature factor of NAG2 is markedly lower than that of those trisaccharides in the HEL complexes.…”

Section: Discussionsupporting

confidence: 77%

“…The face-to-face contact of the sugar ring with aromatic side-chain groups is frequently observed in the structures of sugar-bound proteins. The indole moiety of Trp62 in HEL is stacked with a pyranose ring of trisaccharides and the importance of the hydrophobic contact has been stressed (Ford et al, 1974;Strynadka & James, 1991;Cheetham, Artymiuk & Phillips, 1992). On the other hand, in the TEL-NAG2 complex the pyranose rings of NAG2 face side-chain groups of Asn46, Thr47, Asp48 and Asp52 to stabilize the structure not only by van der Waals forces but also by electrostatic forces between H atoms of the pyranose ring and O atoms of side-chain groups.…”

Section: Discussionmentioning

confidence: 99%

“…The amino-acid sequence in the active-site region is conserved at subsites B-F, but the Aspl01 residue located at the subsite A of HEL is replaced by Gly in TEL. The carboxyl group of Aspl01 forms a hydrogen bond with a sugar residue of NAG3 (Blake et al, 1967;Ford, Johnson, Machin, Phillips & Tjian, 1974;Strynadka & James, 1991;Cheetham, Artymiuk & Phillips, 1992). In the previous paper, we have reported the structure of a monoclinic form of TEL at 1.3 A resolution and demonstrated that the conformation of the region of residues 100-104 differs between TEL and HEL (Harata, 1993).…”

Section: Introductionmentioning

confidence: 93%

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X-ray structure of turkey egg lysozyme complex with di-N-acetyl-chitobiose. Recognition and binding of α-anomeric form

Harata¹,

Muraki²

1995

Acta Cryst D

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The crystalline complex of turkey-egg lysozyme (TEL) with di-N-acetylchitobiose (NAG2) was prepared by a soaking method and the structure was determined by Xray analysis at 1.55/~, resolution. The structure was refined to an R value of 0.175 by simulated annealing and energy minimization. The a-anomer of NAG2 is located at subsite D with the orientation perpendicular to the direction of the active-site cleft. The anomeric residue is deeply inserted into the cleft and the O1 --H hydroxyl group is hydrogen bonded to the carboxyl group of Glu35 which is a catalytic residue. The other sugar residue protrudes outside the cleft and is in van der Waals contact with the E-sheet region comprising of residues 43-53. The binding of NAG2 makes the activesite cleft 0.3-0.5 ,~ narrower and supresses the thermal motion of two lobes constructing the cleft. The NAG2 molecule is bound in a manner not assumed in the catalytic action of the enzyme and the geometry of binding indicates that the a-anomer blocks the active center and acts only as an inhibitor.

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Section: Discussionsupporting

confidence: 77%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 93%

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X-ray structure of turkey egg lysozyme complex with di-N-acetyl-chitobiose. Recognition and binding of α-anomeric form

Harata¹,

Muraki²

1995

Acta Cryst D

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“…The K1 value obtained from these plots was 5.2mM. This may be explained on the basis that the lactone acted as a transition-state analogue as a consequence of its distorted half-chair conformation, in a similar way to that suggested for the lysozyme-catalysed reactions (Ford et al, 1974).…”

Section: Substrate Specificity Ofglucoamylasesupporting

confidence: 61%

Purification and characterization of a thermostable glucoamylase from the thermophilic fungus Thermomyces lanuginosus

Rao¹,

Sastri²,

Rao³

1981

Biochemical Journal

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Glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) was purified from the culture filtrates of the thermophilic fungus Thermomyces lanuginosus and was established to be homogeneous by a number of criteria. The enzyme was a glycoprotein with an average molecular weight of about 57 000 and a carbohydrate content of 10-12%. The enzyme hydrolysed successive glucose residues from the non-reducing ends of the starch molecule. It did not exhibit any glucosyltransferase activity. The enzyme appeared to hydrolyse maltotriose by the multi-chain mechanism. The enzyme was unable to hydrolyse 1,6-alpha-D-glucosidic linkages of isomaltose and dextran. It was optimally active at 70 degrees C. The enzyme exhibited increase in the Vmax. and decreased in Km values with increasing chain length of the substrate molecule. The enzyme was inhibited by the substrate analogue D-glucono-delta-lactone in a non-competitive manner. The enzyme inhibited remarkable resistance towards chemical and thermal denaturation.

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“…The oxocarbonium ion model has been applied to interpret the reaction mechanism of many glycosylases such as lysozyme, 5,6) glucoamylase 7) and glucosidase. 8) In this mechanism, when the glycosidic bond is cleaved, a glycosyl oxocarbonium ion intermediate is formed for catalysis.…”

mentioning

confidence: 99%

Enzymatic Syntheses of Cycloalkyl .BETA.-D-Glucopyranosides and Their Inhibition Activity for Plant .BETA.-Glucosidase

高田¹,

小川²

2004

J. Appl. Glycosci.

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Various models have been proposed for the reaction mechanism of glycosylase in the transition state, 1 4) but a reasonable model remains to be established. The oxocarbonium ion model has been applied to interpret the reaction mechanism of many glycosylases such as lysozyme, 5,6) glucoamylase 7) and glucosidase. 8) In this mechanism, when the glycosidic bond is cleaved, a glycosyl oxocarbonium ion intermediate is formed for catalysis. Evidence of the role of the transition state intermediates came from inhibition studies involving validamine, 9) N substituted valiolamine derivatives, 10) acarbose, 11) nojirimycin, 12) 1 deoxy nojirimycin 13) and N substituted derivatives of 1 deoxynojirimycin. 14) These inhibitors have been designed, synthesized and purified from plant extracts or the culture broth of microorganisms as the analogues of the charge and or the shape of the oxocarbonium ion like transition state intermediates. 15) They have an easily pro-tonated basic nitrogen atom in the position of the anomeric oxygen or the ring oxygen atom. However, the incorporation of a nitrogen positive center into a pyranose ring requires a relatively long reaction sequence. 16) As its structural similarity with the oxocarbonium ion like transition state intermediates, many researchers have performed their inhibition studies on glycosylases using glucono 1,5 lactone. 17 19) This compound is a relatively strong inhibitor toward glucosidases and has no nitrogen atom in a pyranose ring. However, it has been pointed out that their tendency to undergo hydrolytic ring opening under mildly basic conditions and the conversion into glucono 1,4 lactone (inactive) are the great disadvantage of the measurement of inhibition constants. 18,19) We therefore attempted to prepare more convenient glucosidase inhibitors by enzymatic method, which have rather simple chemical structures without a nitrogen atom in the position of the anomeric oxygen or the ring oxygen atom, and are quite stable in an aqueous solution. MATERIALS AND METHODSMaterials. Cyclopropanemethanol (CPAM) was purchased from Kanto Kagaku Co., Ltd. (Japan). Cyclopentanol (CPE) and cyclopentanemethanol (CPEM) were obtained from Lancaster Co., Ltd. (England). p Nitorophenyl glucopyranoside (pNP G) was a product of Nihon Shokuhin Kako Co., Ltd. (Tokyo). The highly purified glucosidases from Aspergillus niger and Trichoderma viride were generous gifts from Dr. T. Unno, Nihon Shokuhin Kako Co., Ltd. (Japan) and Dr. G. Okada, Shizuoka University (Japan), respectively. The purified sweet almond glucosidase was purchased from Sigma Aldrich (USA). These purified glucosidases were used for the inhibitory studies. On the other hand, glucosidases from Trichoderma reesei (Cellcrust) and A. niger (Novozyme 188) were obtained from Novo Nordisk A S, and the enzymes from T. viride (Meicelase) and sweet almond (BGH 101) were purchased from Meiji Seika Kaisha, Ltd. (Japan) and Toyobo Co., Ltd. (Japan), respectively. These enzymes were used for the preparation of cycloalkyl D J. Appl. Glycosci., 5...

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Crystal structure of a lysozyme-tetrasaccharide lactone complex

Cited by 168 publications

References 32 publications

X-ray structure of turkey egg lysozyme complex with di-N-acetyl-chitobiose. Recognition and binding of α-anomeric form

X-ray structure of turkey egg lysozyme complex with di-N-acetyl-chitobiose. Recognition and binding of α-anomeric form

Purification and characterization of a thermostable glucoamylase from the thermophilic fungus Thermomyces lanuginosus

Enzymatic Syntheses of Cycloalkyl .BETA.-D-Glucopyranosides and Their Inhibition Activity for Plant .BETA.-Glucosidase

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