The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity.

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Abstract Text:

Sophie Bozonnet,Morten T Jensen,Morten M Nielsen,Nushin Aghajari,Malene H Jensen,Birte ,Martin ,Samuel Tranier,Richard Haser,Birte Svensson,Sophie Bozonnet,Morten T Jensen,Morten M Nielsen,Nushin Aghajari,Malene H Jensen,Birte ,Martin ,Samuel Tranier,Richard Haser,Birte Svensson,

Some starch-degrading enzymes accommodate carbohydrates at sites situated at a certain distance from the active site. In the crystal structure of barley alpha-amylase 1, oligosaccharide is thus bound to the 'sugar tongs' site. This site on the non-catalytic domain C in the C-terminal part of the molecule contains a key residue, Tyr380, which has numerous contacts with the oligosaccharide. The mutant enzymes Y380A and Y380M failed to bind to beta-cyclodextrin-Sepharose, a starch-mimic resin used for alpha-amylase affinity purification. The K(d) for beta-cyclodextrin binding to Y380A and Y380M was 1.4 mm compared to 0.20-0.25 mm for the wild-type, S378P and S378T enzymes. The substitution in the S378P enzyme mimics Pro376 in the barley alpha-amylase 2 isozyme, which in spite of its conserved Tyr378 did not bind oligosaccharide at the 'sugar tongs' in the structure. Crystal structures of both wild-type and S378P enzymes, but not the Y380A enzyme, showed binding of the pseudotetrasaccharide acarbose at the 'sugar tongs' site. The 'sugar tongs' site also contributed importantly to the adsorption to starch granules, as Kd = 0.47 mg.mL(-1) for the wild-type enzyme increased to 5.9 mg.mL(-1) for Y380A, which moreover catalyzed the release of soluble oligosaccharides from starch granules with only 10% of the wild-type activity. beta-cyclodextrin both inhibited binding to and suppressed activity on starch granules for wild-type and S378P enzymes, but did not affect these properties of Y380A, reflecting the functional role of Tyr380. In addition, the Y380A enzyme hydrolyzed amylose with reduced multiple attack, emphasizing that the 'sugar tongs' participates in multivalent binding of polysaccharide substrates.

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Publishing Authors By Initials

S Bozonnet,MT Jensen,MM Nielsen,N Aghajari,MH Jensen,B ,M ,S Tranier,R Haser,B Svensson,S Bozonnet,MT Jensen,MM Nielsen,N Aghajari,MH Jensen,B ,M ,S Tranier,R Haser,B Svensson,

For similar abstracts research abstracts see: abstracts research

PUBMED ID PMID:

MEDLINE DATE:

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Journal Published:

PUBLICATION TYPE: Research Support, Non-U.S. Gov

Journal: The FEBS journal

VOLUME: 274

Page Numbers: 5055-67

Journal Abbreviation: FEBS J.

ISSN: 1742-464X

DAY: 4

MONTH: 09

YEAR: 2007

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 101229646

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Keywords Mesh Terms:

KEYWORDS:

MESH TERMS:

Chemical & Substance for Abstract: The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity.

AFFILIATION: Enzyme and Protein Chemistry, BioCentrum-DTU, Technical University of Denmark.

Country: England

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: FEBS J

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity Related Publications

• Acetylator phenotype and genotype in HIV-infected patients with and without sulfonamide hypersensitivity.
• Acute aortic syndromes: time to talk of many things.
• An alternative transcript of the FOG-2 gene encodes a FOG-2 isoform lacking the FOG repression motif.
• Asenapine, a novel psychopharmacologic agent: preclinical evidence for clinical effects in schizophrenia.
• Central sensitization phenomena after third molar surgery: A quantitative sensory testing study.
• Denatured hemoproteins as catalysts in lipid oxidation.
• Determination of dextromethorphan and its metabolites in plasma by dual column liquid chromatography and fluorimetric detection.
• Dispatcher-assisted telephone-guided cardiopulmonary resuscitation: an underused lifesaving system.
• Dual effects of nicotine on dopamine neurons mediated by different nicotinic receptor subtypes.
• Effect of a peripheral NMDA receptor antagonist on glutamate-evoked masseter muscle pain and mechanical sensitization in women.
• Effect of arylhydroxylamine metabolites of sulfamethoxazole and dapsone on stress signal expression in human keratinocytes.
• Effect of conditioning electrical stimuli on temporalis electromyographic activity during sleep.
• Effects of local anesthetics on somatosensory function in the temporomandibular joint area.
• Efficacy and safety of anticoagulant prophylaxis to prevent venous thromboembolism in acutely ill medical inpatients: a meta-analysis.
• FOG-2 attenuates endothelial-to-mesenchymal transformation in the endocardial cushions of the developing heart.
• Formation and uptake of arylhydroxylamine-haptenated proteins in human dendritic cells.
• General intellectual capacity of young men with cleft lip with or without cleft palate and cleft palate alone.
• Human papillomavirus (HPV), DNA aberrations and cell cycle progression in anal squamous cell carcinoma patients.
• Hypersensitivity to Mechanical and Intra-articular Electrical Stimuli in Persons with Painful Temporomandibular Joints.
• Individuals with selective IgA deficiency resolve rotavirus disease and develop higher antibody titers (IgG, IgG1) than IgA competent individuals.
• Spatio-temporal changes in germination and radical elongation of barley seeds tracked by proteome analysis of dissected embryo, aleurone layer, and endosperm tissues.
• Speech results in adult Swedish patients born with unilateral complete cleft lip and palate.
• Survival is similar after standard treatment and chest compression only in out-of-hospital bystander cardiopulmonary resuscitation.
• The 'pair of sugar tongs' site on the non-catalytic domain C of barley alpha-amylase participates in substrate binding and activity.
• The Second JOR Summer School Review Series.
• The impact of pain and depression on assessment of rehabilitation need: a cross-sectional study in long-term sick-listed patients.
• Vagal influences on gastric acid secretion. Experimental studies in cats.
• Vertical structure of recent Arctic warming.
• [In Process Citation]
• [Not Available.]