scholarly journals Structural analysis of β-glucosidase mutants derived from a hyperthermophilic tetrameric structure

2014 ◽  
Vol 70 (3) ◽  
pp. 877-888 ◽  
Author(s):  
Makoto Nakabayashi ◽  
Misumi Kataoka ◽  
Yumiko Mishima ◽  
Yuka Maeno ◽  
Kazuhiko Ishikawa
Keyword(s):  
Crystal Structure ◽  
Pyrococcus Furiosus ◽  
Structural Data ◽  
Biochemical Properties ◽  
Intrinsic Activity ◽  
Oligomeric Structure ◽  
Tetrameric Structure ◽  
Crystal Structural Data ◽  
Dimeric Form

β-Glucosidase fromPyrococcus furiosus(BGLPf) is a hyperthermophilic tetrameric enzyme which can degrade cellooligosaccharides to glucose under hyperthermophilic conditions and thus holds promise for the saccharification of lignocellulosic biomass at high temperature. Prior to the production of large amounts of this enzyme, detailed information regarding the oligomeric structure of the enzyme is required. Several crystals of BGLPf have been prepared over the past ten years, but its crystal structure had not been solved until recently. In 2011, the first crystal structure of BGLPf was solved and a model was constructed at somewhat low resolution (2.35 Å). In order to obtain more detailed structural data on BGLPf, the relationship between its tetrameric structure and the quality of the crystal was re-examined. A dimeric form of BGLPf was constructed and its crystal structure was solved at a resolution of 1.70 Å using protein-engineering methods. Furthermore, using the high-resolution crystal structural data for the dimeric form, a monomeric form of BGLPf was constructed which retained the intrinsic activity of the tetrameric form. The thermostability of BGLPf is affected by its oligomeric structure. Here, the biophysical and biochemical properties of engineered dimeric and monomeric BGLPfs are reported, which are promising prototype models to apply to the saccharification reaction. Furthermore, details regarding the oligomeric structures of BGLPf and the reasons why the mutations yielded improved crystal structures are discussed.

scholarly journals Monomer structure of a hyperthermophilic β-glucosidase mutant forming a dodecameric structure in the crystal form

2014 ◽  
Vol 70 (7) ◽  
pp. 854-859
Author(s):  
Makoto Nakabayashi ◽  
Misumi Kataoka ◽  
Masahiro Watanabe ◽  
Kazuhiko Ishikawa
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Pyrococcus Furiosus ◽  
Crystal Form ◽  
Mutant Enzyme ◽  
Monomeric Form ◽  
Asymmetric Unit ◽  
Oligomeric Structure ◽  
Space Group ◽  
Monomer Structure

One of the β-glucosidases fromPyrococcus furiosus(BGLPf) is found to be a hyperthermophilic tetrameric enzyme that can degrade cellooligosaccharides. Recently, the crystal structures of the tetrameric and dimeric forms were solved. Here, a new monomeric form of BGLPf was constructed by removing the C-terminal region of the enzyme and its crystal structure was solved at a resolution of 2.8 Å in space groupP1. It was discovered that the mutant enzyme forms a unique dodecameric structure consisting of two hexameric rings in the asymmetric unit of the crystal. Under biological conditions, the mutant enzyme forms a monomer. This result helps explain how BGLPf has attained its oligomeric structure and thermostability.

Crystal structure of the wild-type and D30A mutant thioredoxin h of Chlamydomonas reinhardtii and implications for the catalytic mechanism

2001 ◽  
Vol 359 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Valeria MENCHISE ◽  
Catherine CORBIER ◽  
Claude DIDIERJEAN ◽  
Michele SAVIANO ◽  
Ettore BENEDETTI ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Proton Transfer ◽  
Chlamydomonas Reinhardtii ◽  
Catalytic Mechanism ◽  
Structural Data ◽  
Careful Analysis ◽  
Wild Type ◽  
Thioredoxin H ◽  
Dynamics Simulations

Thioredoxins are ubiquitous proteins which catalyse the reduction of disulphide bridges on target proteins. The catalytic mechanism proceeds via a mixed disulphide intermediate whose breakdown should be enhanced by the involvement of a conserved buried residue, Asp-30, as a base catalyst towards residue Cys-39. We report here the crystal structure of wild-type and D30A mutant thioredoxin h from Chlamydomonas reinhardtii, which constitutes the first crystal structure of a cytosolic thioredoxin isolated from a eukaryotic plant organism. The role of residue Asp-30 in catalysis has been revisited since the distance between the carboxylate OD1 of Asp-30 and the sulphur SG of Cys-39 is too great to support the hypothesis of direct proton transfer. A careful analysis of all available crystal structures reveals that the relative positioning of residues Asp-30 and Cys-39 as well as hydrophobic contacts in the vicinity of residue Asp-30 do not allow a conformational change sufficient to bring the two residues close enough for a direct proton transfer. This suggests that protonation/deprotonation of Cys-39 should be mediated by a water molecule. Molecular-dynamics simulations, carried out either in vacuo or in water, as well as proton-inventory experiments, support this hypothesis. The results are discussed with respect to biochemical and structural data.

Structural Studies on N-(2,4,6-Trimethylphenyl)-methyl/ chloro-acetamides, 2,4,6-(CH3)3C6H2NH-CO-CH3–yXy (X = CH3 or Cl and y = 0, 1, 2)

2006 ◽  
Vol 61 (10-11) ◽  
pp. 588-594 ◽  
Author(s):  
Basavalinganadoddy Thimme Gowda ◽  
Jozef Kožíšek ◽  
Hartmut Fuess
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Data ◽  
The Other ◽  
Side Chain ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
Lattice Constants ◽  
Peptide Linkage ◽  
The Mean

TMPAThe effect of substitutions in the ring and in the side chain on the crystal structure of N- (2,4,6-trimethylphenyl)-methyl/chloro-acetamides of the configuration 2,4,6-(CH3)3C6H2NH-COCH3− yXy (X = CH3 or Cl and y = 0,1, 2) has been studied by determining the crystal structures of N-(2,4,6-trimethylphenyl)-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH3 (); N-(2,4,6- trimethylphenyl)-2-methylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2-CH3 (TMPMA); N-(2,4,6- trimethylphenyl)-2,2-dimethylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH(CH3)2 (TMPDMA) and N-(2,4,6-trimethylphenyl)-2,2-dichloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CHCl2 (TMPDCA). The crystallographic system, space group, formula units and lattice constants in Å are: TMPA: monoclinic, Pn, Z = 2, a = 8.142(3), b = 8.469(3), c = 8.223(3), β = 113.61(2)◦; TMPMA: monoclinic, P21/n, Z = 8, a = 9.103(1), b = 15.812(2), c = 16.4787(19), α = 89.974(10)◦, β = 96.951(10)◦, γ =89.967(10)◦; TMPDMA: monoclinic, P21/c, Z = 4, a =4.757(1), b= 24.644(4), c =10.785(2), β = 99.647(17)◦; TMPDCA: triclinic, P¯1, Z = 2, a = 4.652(1), b = 11.006(1), c = 12.369(1), α = 82.521(7)◦, β = 83.09(1)◦, γ = 79.84(1)◦. The results are analyzed along with the structural data of N-phenylacetamide, C6H5NH-CO-CH3; N-(2,4,6-trimethylphenyl)-2-chloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)-acetamide, 2,4,6-Cl3C6H2NH-COCH3; N-(2,4,6-trichlorophenyl)-2-chloroacetamide, 2,4,6-Cl3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)- 2,2-dichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CHCl2 and N-(2,4,6-trichlorophenyl)- 2,2,2-trichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CCl3. TMPA, TMPMA and TMPDCA have one molecule each in their asymmetric units, while TMPDMA has two molecules in its asymmetric unit. Changes in the mean ring distances are smaller on substitution as the effect has to be transmitted through the peptide linkage. The comparison of the other bond parameters reveal that there are significant changes in them on substitution.

scholarly journals Specificity of Human Sulfiredoxin for Reductant and Peroxiredoxin Oligomeric State

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 946
Author(s):  
Tom E. Forshaw ◽  
Julie A. Reisz ◽  
Kimberly J. Nelson ◽  
Rajesh Gumpena ◽  
J. Reed Lawson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Antioxidant Enzymes ◽  
Hydrogen Sulfide ◽  
Active Site ◽  
Relative Efficacy ◽  
Oligomeric Structure ◽  
Cellular Functions ◽  
Oligomeric State ◽  
Structural Requirements ◽  
First Time

Human peroxiredoxins (Prx) are a family of antioxidant enzymes involved in a myriad of cellular functions and diseases. During the reaction with peroxides (e.g., H2O2), the typical 2-Cys Prxs change oligomeric structure between higher order (do)decamers and disulfide-linked dimers, with the hyperoxidized inactive state (-SO2H) favoring the multimeric structure of the reduced enzyme. Here, we present a study on the structural requirements for the repair of hyperoxidized 2-Cys Prxs by human sulfiredoxin (Srx) and the relative efficacy of physiological reductants hydrogen sulfide (H2S) and glutathione (GSH) in this reaction. The crystal structure of the toroidal Prx1-Srx complex shows an extended active site interface. The loss of this interface within engineered Prx2 and Prx3 dimers yielded variants more resistant to hyperoxidation and repair by Srx. Finally, we reveal for the first time Prx isoform-dependent use of and potential cooperation between GSH and H2S in supporting Srx activity.

scholarly journals Comparative effects on storage period of varieties Pineapple fruits

2015 ◽  
Vol 2 (3) ◽  
pp. 395-410 ◽  
Author(s):  
Shah Md Yusuf Ali ◽  
Md Ahiduzzaman ◽  
Sharmin Akhter ◽  
M Abdul Matin Biswas ◽  
Nafis Iqbal ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Storage Period ◽  
Biochemical Properties ◽  
Overall Acceptability ◽  
Pineapple Juice ◽  
Physico Chemical ◽  
Pineapple Fruit ◽  
Sensorial Attributes ◽  
The Comparative Study

Pineapple is considered as one of the most wanted tropical fruits and it is widely taken for fresh consumption as well as their flesh and juice are used for preparation of different product in Agro-processing industries. For such industrial processes, it is important to know the information of characteristics changes of pineapple during day after storage. Four varieties of pineapple were collected from different areas of Bangladesh named Honey Queen (H.Q), Giant Kew (G.K), Asshini and Ghorasal. Some Physico-chemical properties (weight loss, moisture content, ash and edible portion, pH, TSS, titrable acidity (TA), total sugar, reducing sugar) biochemical properties (ascorbic acid) and sensorial attributes (color, odor, firmness, appearances, sweetness and overall acceptability) of pineapple juice were studied during day after storage. This study examined the Comparison of different varieties of pineapple fruit characteristics and sensory quality of the pineapple fruits during storage. It was shown that there was a significant changes between the storage periods in relation to different varieties of fruits. The firmness of pineapple fruits were in outside and inside to be 0.21 to 0.27 N/m2 and 0.06 to 0.10 N/m2, respectively. The pH values of different varieties were found to be in the range of 4.30 to 4.36. The highest and lowest sweetness index were estimated to be 36.30 and 22.15 for Honey Queen and Asshini respectively. The highest and lowest magnitude of sugar contents of four pineapple varieties were found to be in the range of 14.16 to 15.8 mg/100g.The average TSS values were found to be 15.12%, 12.33%, 13.14% and 12.95% for H.Q., G.K., Asshini and Ghorashal, respectively. The comparative study indicated the characteristics of different varieties of pineapple changes during after storage.Res. Agric., Livest. Fish.2(3): 395-410, December 2015

Crystal Structure of Wheat Glutaredoxin and Its Application in Improving the Processing Quality of Flour

2018 ◽  
Vol 66 (45) ◽  
pp. 12079-12087 ◽  
Author(s):  
Xiaomei Sun ◽  
Meirong Chen ◽  
Feng Jia ◽  
Yi Hou ◽  
Song-Qing Hu
Keyword(s):  
Crystal Structure ◽  
Processing Quality

scholarly journals Crystal structure of a dimeric form of streptococcal pyrogenic exotoxin A (SpeA1)

2004 ◽  
Vol 13 (9) ◽  
pp. 2285-2290 ◽  
Author(s):  
Matthew D. Baker ◽  
Inessa Gendlina ◽  
Carleen M. Collins ◽  
K. Ravi Acharya
Keyword(s):  
Crystal Structure ◽  
Exotoxin A ◽  
Dimeric Form

scholarly journals The Crystal Structure of the Secreted Dimeric Form of the Hemophore HasA Reveals a Domain Swapping with an Exchanged Heme Ligand

2007 ◽  
Vol 365 (4) ◽  
pp. 1176-1186 ◽  
Author(s):  
Mirjam Czjzek ◽  
Sylvie Létoffé ◽  
Cécile Wandersman ◽  
Muriel Delepierre ◽  
Anne Lecroisey ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Domain Swapping ◽  
Dimeric Form

scholarly journals Reverse Osmosis of Whey - Valuable Biocomponent of Feed and Food

2020 ◽  
Vol 70 (12) ◽  
pp. 4482-4487
Keyword(s):  
Reverse Osmosis ◽  
Biochemical Properties ◽  
Animal Nutrition ◽  
Antioxidant Compounds ◽  
Cheese Industry ◽  
Animal Feeding ◽  
Western Romania ◽  
Technological Options

Whey is a high-quality dairy by-product from cheese industry, being an important source of valuable proteins. It is important in human and animal nutrition due to its content in enzymes, hormones, vitamins, minerals, and antioxidant compounds, it has low lactose content, very little or it is free of lipids, but the dehydration (drying) technique must be very well chosen to preserve the quantity and quality of components. The objective of our study was to analyze the possibility of concentrating whey by reverse osmosis and having in view the possibility to preserve most of the biochemical properties of whey. Thus, we made comparative tests for quantitative determination of total protein, lipids, pH and acidity for - raw, skimmed and concentrated whey. The results showed that reverse osmosis is a good, cheap and easy-to-use method in cheese factories to obtain whey with well-preserved components. Most of the farmers from western Romania (especially in Timis county) use whey as ingredient of feed products. Studies from previous years present whey as an ingredient of nutritional supplements for animal feeding plan, as well as an ingredient in supplements for athletes and alternative medicine. There are many technological options for whey processing, but the final option must be very well correlated with the final nutritional purpose. Keywords: whey, feed, human, nutrition

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