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Yousif AM, Evans DE. Changes in malt quality during production in two commercial malt houses. JOURNAL OF THE INSTITUTE OF BREWING 2020. [DOI: 10.1002/jib.609] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Adel M. Yousif
- Australian Export Grains Innovation Centre; 3 Baron-Hay Court South Perth WA 6151 Australia
- Tasmanian Institute of Agriculture, College of Science and Engineering; University of Tasmania; Sandy Bay Campus TAS 7005 Australia
| | - D. Evan Evans
- The Tassie Beer Dr Consulting; 15 Rianna Road Lindisfarne Tasmania 7015 Australia
- School of Natural Sciences; University of Tasmania; Sandy Bay Tasmania 7005 Australia
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2
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Cornaggia C, Evans DE, Draga A, Mangan D, McCleary BV. Prediction of potential malt extract and beer filterability using conventional and novel malt assays. JOURNAL OF THE INSTITUTE OF BREWING 2019. [DOI: 10.1002/jib.567] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - D. Evan Evans
- The Tassie Beer Dr Consulting; 15 Rianna Road Lindisfarne Tasmania 7015 Australia
- School of Natural Sciences, University of Tasmania; Private Bag 55 Hobart Tasmania 7001 Australia
| | - Anna Draga
- Megazyme u.c., Bray Business Park; Bray Co. Wicklow Ireland
| | - David Mangan
- Megazyme u.c., Bray Business Park; Bray Co. Wicklow Ireland
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3
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Lauer JC, Cu S, Burton RA, Eglinton JK. Variation in barley (1 → 3, 1 → 4)-β-glucan endohydrolases reveals novel allozymes with increased thermostability. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2017; 130:1053-1063. [PMID: 28239779 DOI: 10.1007/s00122-017-2870-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 02/02/2017] [Indexed: 06/06/2023]
Abstract
Novel barley (1 → 3, 1 → 4)-β-glucan endohydrolases with increased thermostability. Rapid and reliable degradation of (1 → 3, 1 → 4)-β-glucan to produce low viscosity wort is an essential requirement for malting barley. The (1 → 3, 1 → 4)-β-glucan endohyrolases are responsible for the primary hydrolysis of cell wall β-glucan. The variation in β-glucanase genes HvGlb1 and HvGlb2 that encode EI and EII, respectively, were examined in elite and exotic germplasm. Six EI and 14 EII allozymes were identified, and significant variation was found in β-glucanase from Hordeum vulgare ssp. spontaneum (wild barley), the progenitor of modern cultivated barley. Allozymes were examined using prediction methods; the change in Gibbs free energy of the identified amino acid substitutions to predict changes in enzyme stability and homology modelling to examine the structure of the novel allozymes using the existing solved EII structure. Two EI and four EII allozymes in wild barley accessions were predicted to have improved barley β-glucanase thermostability. One novel EII candidate was identified in existing backcross lines with contrasting HvGlb2 alleles from wild barley and cv Flagship. The contrasting alleles in selected near isogenic lines were examined in β-glucanase thermostability analyses. The EII from wild barley exhibited a significant increase in β-glucanase thermostability conferred by the novel HvGlb2 allele. Increased β-glucanase thermostability is heritable and candidates identified in wild barley could improve malting and brewing quality in new varieties.
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Affiliation(s)
- Juanita C Lauer
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA, 5064, Australia.
| | - Suong Cu
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA, 5064, Australia
| | - Rachel A Burton
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA, 5064, Australia
| | - Jason K Eglinton
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA, 5064, Australia
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Lauer JC, Yap K, Cu S, Burton RA, Eglinton JK. Novel Barley (1→3,1→4)-β-Glucan Endohydrolase Alleles Confer Increased Enzyme Thermostability. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:421-428. [PMID: 27936680 DOI: 10.1021/acs.jafc.6b04287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Barley (1→3,1→4)-β-glucan endohydrolases (β-glucanases; EI and EII) are primarily responsible for hydrolyzing high molecular weight (1→3,1→4)-β-glucans (β-glucan) during germination. Incomplete endosperm modification during malting results in residual β-glucan that can contribute to increased wort viscosity and beer chill haze. Four newly identified forms of EI and EII and the reference enzymes EI-a and EII-a were expressed in Escherichia coli, and the recombinant proteins were characterized for enzyme kinetics and thermostability. EI and EII variants that exhibited higher residual β-glucanase activity than EI-a and EII-a after heat treatment also exhibited increased substrate affinity and decreased turnover rates. The novel EII-l form exhibited significantly increased thermostability compared with the reference EII-a when activity was measured at elevated temperature. EII-l exhibited a T50 value, which indicates the temperature at which 50% of β-glucanase activity remains, 1.3 °C higher than that of EII-a. The irreversible thermal inactivation difference between EII-a and EII-l after 5 min of heat treatment at 56 °C was 11.9%. The functional significance of the three amino acid differences between EII-a and EII-l was examined by making combinatorial mutations in EII-a using site-directed mutagenesis. The S20G and D284E amino acid substitutions were shown to be responsible for the increase in EII-1 thermostability.
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Affiliation(s)
- Juanita C Lauer
- School of Agriculture, Food & Wine, The University of Adelaide , Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia
| | - Kuok Yap
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food & Wine, The University of Adelaide , Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia
| | - Suong Cu
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food & Wine, The University of Adelaide , Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia
| | - Rachel A Burton
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food & Wine, The University of Adelaide , Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia
| | - Jason K Eglinton
- School of Agriculture, Food & Wine, The University of Adelaide , Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia
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5
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Gorjanović S. A Review: Biological and Technological Functions of Barley Seed Pathogenesis-Related Proteins (PRs). JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2009.tb00389.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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6
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Hrmova M, Fincher GB. Functional genomics and structural biology in the definition of gene function. Methods Mol Biol 2009; 513:199-227. [PMID: 19347658 DOI: 10.1007/978-1-59745-427-8_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
By mid-2007, the three-dimensional (3D) structures of some 45,000 proteins have been solved, over a period where the linear structures of millions of genes have been defined. Technical challenges associated with X-ray crystallography are being overcome and high-throughput methods both for crystallization of proteins and for solving their 3D structures are under development. The question arises as to how structural biology can be integrated with and adds value to functional genomics programs. Structural biology will assist in the definition of gene function through the identification of the likely function of the protein products of genes. The 3D information allows protein sequences predicted from DNA sequences to be classified into broad groups, according to the overall 'fold', or 3D shape, of the protein. Structural information can be used to predict the preferred substrate of a protein, and thereby greatly enhance the accurate annotation of the corresponding gene. Furthermore, it will enable the effects of amino acid substitutions in enzymes to be better understood with respect to enzyme function and could thereby provide insights into natural variation in genes. If the molecular basis of transcription factor-DNA interactions were defined through precise 3D knowledge of the protein-DNA binding site, it would be possible to predict the effects of base substitutions within the motif on the specificity and/or kinetics of binding. In this chapter, we present specific examples of how structural biology can provide valuable information for functional genomics programs.
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Affiliation(s)
- Maria Hrmova
- Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
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7
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Burton RA, Collins HM, Fincher GB. The Role of Endosperm Cell Walls in Barley Malting Quality. ADVANCED TOPICS IN SCIENCE AND TECHNOLOGY IN CHINA 2009. [DOI: 10.1007/978-3-642-01279-2_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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8
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Prajapati RS, Das M, Sreeramulu S, Sirajuddin M, Srinivasan S, Krishnamurthy V, Ranjani R, Ramakrishnan C, Varadarajan R. Thermodynamic effects of proline introduction on protein stability. Proteins 2007; 66:480-91. [PMID: 17034035 DOI: 10.1002/prot.21215] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The amino acid Pro is more rigid than other naturally occurring amino acids and, in proteins, lacks an amide hydrogen. To understand the structural and thermodynamic effects of Pro substitutions, it was introduced at 13 different positions in four different proteins, leucine-isoleucine-valine binding protein, maltose binding protein, ribose binding protein, and thioredoxin. Three of the maltose binding protein mutants were characterized by X-ray crystallography to confirm that no structural changes had occurred upon mutation. In the remaining cases, fluorescence and CD spectroscopy were used to show the absence of structural change. Stabilities of wild type and mutant proteins were characterized by chemical denaturation at neutral pH and by differential scanning calorimetry as a function of pH. The mutants did not show enhanced stability with respect to chemical denaturation at room temperature. However, 6 of the 13 single mutants showed a small but significant increase in the free energy of thermal unfolding in the range of 0.3-2.4 kcal/mol, 2 mutants showed no change, and 5 were destabilized. In five of the six cases, the stabilization was because of reduced entropy of unfolding. However, the magnitude of the reduction in entropy of unfolding was typically several fold larger than the theoretical estimate of -4 cal K(-1) mol(-1) derived from the relative areas in the Ramachandran map accessible to Pro and Ala residues, respectively. Two double mutants were constructed. In both cases, the effects of the single mutations on the free energy of thermal unfolding were nonadditive.
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Goihberg E, Dym O, Tel-Or S, Levin I, Peretz M, Burstein Y. A single proline substitution is critical for the thermostabilization of Clostridium beijerinckii alcohol dehydrogenase. Proteins 2006; 66:196-204. [PMID: 17063493 DOI: 10.1002/prot.21170] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Analysis of the three-dimensional structures of three closely related mesophilic, thermophilic, and hyperthermophilic alcohol dehydrogenases (ADHs) from the respective microorganisms Clostridium beijerinckii (CbADH), Entamoeba histolytica (EhADH1), and Thermoanaerobacter brockii (TbADH) suggested that a unique, strategically located proline residue (Pro100) might be crucial for maintaining the thermal stability of EhADH1. To determine whether proline substitution at this position in TbADH and CbADH would affect thermal stability, we used site-directed mutagenesis to replace the complementary residues in both enzymes with proline. The results showed that replacing Gln100 with proline significantly enhanced the thermal stability of the mesophilic ADH: DeltaT(1/2) (60 min) = + 8 degrees C (temperature of 50% inactivation after incubation for 60 min), DeltaT(1/2) (CD) = +11.5 degrees C (temperature at which 50% of the original CD signal at 218 nm is lost upon heating between 30 degrees and 98 degrees C). A His100 --> Pro substitution in the thermophilic TbADH had no effect on its thermostability. An analysis of the three-dimensional structure of the crystallized thermostable mutant Q100P-CbADH suggested that the proline residue at position 100 stabilized the enzyme by reinforcing hydrophobic interactions and by reducing the flexibility of a loop at this strategic region.
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Affiliation(s)
- Edi Goihberg
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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Minic Z, Jouanin L. Plant glycoside hydrolases involved in cell wall polysaccharide degradation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2006; 44:435-49. [PMID: 17023165 DOI: 10.1016/j.plaphy.2006.08.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Indexed: 05/12/2023]
Abstract
The cell wall plays a key role in controlling the size and shape of the plant cell during plant development and in the interactions of the plant with its environment. The cell wall structure is complex and contains various components such as polysaccharides, lignin and proteins whose composition and concentration change during plant development and growth. Many studies have revealed changes in cell walls which occur during cell division, expansion, and differentiation and in response to environmental stresses; i.e. pathogens or mechanical stress. Although many proteins and enzymes are necessary for the control of cell wall organization, little information is available concerning them. An important advance was made recently concerning cell wall organization as plant enzymes that belong to the superfamily of glycoside hydrolases and transglycosidases were identified and characterized; these enzymes are involved in the degradation of cell wall polysaccharides. Glycoside hydrolases have been characterized using molecular, genetic and biochemical approaches. Many genes encoding these enzymes have been identified and functional analysis of some of them has been performed. This review summarizes our current knowledge about plant glycoside hydrolases that participate in the degradation and reorganisation of cell wall polysaccharides in plants focussing particularly on those from Arabidopsis thaliana.
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Affiliation(s)
- Z Minic
- Laboratoire de biologie cellulaire, Institut national de la recherche agronomique, route de Saint-Cyr, 78026 Versailles cedex, France
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11
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Burton RA, Wilson SM, Hrmova M, Harvey AJ, Shirley NJ, Medhurst A, Stone BA, Newbigin EJ, Bacic A, Fincher GB. Cellulose synthase-like CslF genes mediate the synthesis of cell wall (1,3;1,4)-beta-D-glucans. Science 2006; 311:1940-2. [PMID: 16574868 DOI: 10.1126/science.1122975] [Citation(s) in RCA: 272] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A characteristic feature of grasses and commercially important cereals is the presence of (1,3;1,4)-beta-d-glucans in their cell walls. We have used comparative genomics to link a major quantitative trait locus for (1,3;1,4)-beta-d-glucan content in barley grain to a cluster of cellulose synthase-like CslF genes in rice. After insertion of rice CslF genes into Arabidopsis, we detected (1,3;1,4)-beta-d-glucan in walls of transgenic plants using specific monoclonal antibodies and enzymatic analysis. Because wild-type Arabidopsis does not contain CslF genes or have (1,3;1,4)-beta-d-glucans in its walls, these experiments provide direct, gain-of-function evidence for the participation of rice CslF genes in (1,3;1,4)-beta-d-glucan biosynthesis.
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Affiliation(s)
- Rachel A Burton
- Australian Centre for Plant Functional Genomics; School of Agriculture, Food, and Wine; University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
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12
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Hytönen VP, Nyholm TKM, Pentikäinen OT, Vaarno J, Porkka EJ, Nordlund HR, Johnson MS, Slotte JP, Laitinen OH, Kulomaa MS. Chicken Avidin-related Protein 4/5 Shows Superior Thermal Stability when Compared with Avidin while Retaining High Affinity to Biotin. J Biol Chem 2004; 279:9337-43. [PMID: 14660583 DOI: 10.1074/jbc.m310989200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protein chicken avidin is a commonly used tool in various applications. The avidin gene belongs to a gene family that also includes seven other members known as the avidin-related genes (AVR). We report here on the extremely high thermal stability and functional characteristics of avidin-related protein AVR4/5, a member of the avidin protein family. The thermal stability characteristics of AVR4/5 were examined using a differential scanning calorimeter, microparticle analysis, and a microplate assay. Its biotin-binding properties were studied using an isothermal calorimeter and IAsys optical biosensor. According to these analyses, in the absence of biotin AVR4/5 is clearly more stable (T(m) = 107.4 +/- 0.3 degrees C) than avidin (T(m) = 83.5 +/- 0.1 degrees C) or bacterial streptavidin (T(m) = 75.5 degrees C). AVR4/5 also exhibits a high affinity for biotin (K(d) approximately 3.6 x 10(-14) m) comparable to that of avidin and streptavidin (K(d) approximately 10(-15) m). Molecular modeling and site-directed mutagenesis were used to study the molecular details behind the observed high thermostability. The results indicate that AVR4/5 and its mutants have high potential as new improved tools for applications where exceptionally high stability and tight biotin binding are needed.
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Affiliation(s)
- Vesa P Hytönen
- Department of Biological and Environmental Science, P. O. Box 35 (YAB), FIN-40014 University of Jyväskylä, Finland
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Mozo-Villarías A, Cedano J, Querol E. A simple electrostatic criterion for predicting the thermal stability of proteins. Protein Eng Des Sel 2003; 16:279-86. [PMID: 12736371 DOI: 10.1093/proeng/gzg033] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The enhancement of protein thermostability is an important issue for both basic science and biotechnology purposes. We have developed a thermostability criterion for a protein in terms of a quasi-electric dipole moment (contributed by its charged residues) defined for an electric charge distribution whose total charge is not zero. It was found that minimization of the modulus of this dipole moment increased its thermal stability, as demonstrated by surveying these values in pairs of mesostable-thermostable homologous proteins and in mutations described in the literature. The analysis of these observations provides criteria for thermostabilization of a protein, by computing its dipole profile. This profile is obtained by direct substitution of each amino acid of the sequence by either a positive, negative or neutral amino acid, followed by a recalculation of the dipole moment. As an experimental example, these criteria were applied to a beta-glucanase to enhance its thermal stability.
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Affiliation(s)
- Angel Mozo-Villarías
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, Avda. Rovira Roure 44, 25198 Lleida, Spain.
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14
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Hrmova M, Imai T, Rutten SJ, Fairweather JK, Pelosi L, Bulone V, Driguez H, Fincher GB. Mutated barley (1,3)-beta-D-glucan endohydrolases synthesize crystalline (1,3)-beta-D-glucans. J Biol Chem 2002; 277:30102-11. [PMID: 12023973 DOI: 10.1074/jbc.m203971200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Barley (1,3)-beta-D-glucan endohydrolases (EC ), inactivated by site-directed mutagenesis of their catalytic nucleophiles, show autocondensation glucosynthetic activity with alpha-laminaribiosyl fluoride and heterocondensation glycosynthetic activity with alpha-laminaribiosyl fluoride and 4'-nitrophenyl beta-D-glucopyranoside. The native enzyme is a retaining endohydrolase of the family 17 group and catalyzes glycosyl transfer reactions at high substrate concentrations. Catalytic efficiencies (k(cat) K(m)(-1)) of mutants E231G, E231S, and E231A as glycosynthases are 28.9, 0.9, and 0.5 x 10(-4) m(-1) s(-1), respectively. Glycosynthase reactions appear to be processive and proceed with pH optima of 6-8 and yields of up to 75%. Insoluble products formed during the glycosynthase reaction appear as lamellar, hexagonal crystals when observed by electron microscopy. Methylation, NMR, and matrix-assisted laser desorption ionization time-of-flight analyses show that the reaction products are linear (1,3)-beta-D-glucans with a degree of polymerization of 30-34, whereas electron and x-ray diffraction patterns indicate that these (1,3)-beta-D-glucan chains adopt a parallel, triple helical conformation. The (1,3)-beta-D-glucan triple helices are orientated perpendicularly to the plane of the lamellar crystals. The barley (1,3)-beta-D-glucan glycosynthases have considerable potential for tailored and high efficiency synthesis of (1,3)-beta-D-linked oligo- and polysaccharides, some of which could have immunomodulating activity, or for the coupling of (1,3)-beta-D-linked glucosyl residues onto other oligosaccharides or glycoproteins.
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Affiliation(s)
- Maria Hrmova
- Department of Plant Science, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia
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15
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Abstract
There are many ways to select mutations that increase the stability of proteins, including rational design, functional screening of randomly generated mutant libraries, and comparison of naturally occurring homologous proteins. The protein engineer's toolbox is expanding and the number of successful examples of engineered protein stability is increasing. Still, the selection of thermostable mutations is not a standard process. Selection is complicated by lack of knowledge of the process that leads to thermal inactivation and by the fact that proteins employ a large variety of structural tricks to achieve stability.
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