scholarly journals Carbohydrate-binding modules targeting branched polysaccharides: overcoming side-chain recalcitrance in a non-catalytic approach

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jiawen Liu ◽  
Di Sun ◽  
Jingrong Zhu ◽  
Cong Liu ◽  
Weijie Liu
Keyword(s):  
Side Chain ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Enzymatic Conversion ◽  
Type Iii ◽  
Debranching Enzymes ◽  
Ligand Type ◽  
Carbohydrate Binding Modules ◽  
Hydrolysis Of ◽  
Main Strategy

AbstractExtensive decoration of backbones is a major factor resulting in resistance of enzymatic conversion in hemicellulose and other branched polysaccharides. Employing debranching enzymes is the main strategy to overcome this kind of recalcitrance at present. A carbohydrate-binding module (CBM) is a contiguous amino acid sequence that can promote the binding of enzymes to various carbohydrates, thereby facilitating enzymatic hydrolysis. According to previous studies, CBMs can be classified into four types based on their preference in ligand type, where Type III and IV CBMs prefer to branched polysaccharides than the linear and thus are able to specifically enhance the hydrolysis of substrates containing side chains. With a role in dominating the hydrolysis of branched substrates, Type III and IV CBMs could represent a non-catalytic approach in overcoming side-chain recalcitrance.

scholarly journals The family 42 carbohydrate-binding module of family 54 α-L-arabinofuranosidase specifically binds the arabinofuranose side chain of hemicellulose

2006 ◽  
Vol 399 (3) ◽  
pp. 503-511 ◽  
Author(s):  
Akimasa Miyanaga ◽  
Takuya Koseki ◽  
Yozo Miwa ◽  
Yuichiro Mese ◽  
Sachiko Nakamura ◽  
...  
Keyword(s):  
Binding Pocket ◽  
Side Chain ◽  
Titration Calorimetry ◽  
Glycoside Hydrolase Family ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Binding Assays ◽  
The Family ◽  
Affinity Gel Electrophoresis ◽  
Hydrolysis Of

α-L-Arabinofuranosidase catalyses the hydrolysis of the α-1,2-, α-1,3-, and α-1,5-L-arabinofuranosidic bonds in L-arabinose-containing hemicelluloses such as arabinoxylan. AkAbf54 (the glycoside hydrolase family 54 α-L-arabinofuranosidase from Aspergillus kawachii) consists of two domains, a catalytic and an arabinose-binding domain. The latter has been named AkCBM42 [family 42 CBM (carbohydrate-binding module) of AkAbf54] because homologous domains are classified into CBM family 42. In the complex between AkAbf54 and arabinofuranosyl-α-1,2-xylobiose, the arabinose moiety occupies the binding pocket of AkCBM42, whereas the xylobiose moiety is exposed to the solvent. AkCBM42 was found to facilitate the hydrolysis of insoluble arabinoxylan, because mutants at the arabinose binding site exhibited markedly decreased activity. The results of binding assays and affinity gel electrophoresis showed that AkCBM42 interacts with arabinose-substituted, but not with unsubstituted, hemicelluloses. Isothermal titration calorimetry and frontal affinity chromatography analyses showed that the association constant of AkCBM42 with the arabinose moiety is approximately 103 M−1. These results indicate that AkCBM42 binds the non-reducing-end arabinofuranosidic moiety of hemicellulose. To our knowledge, this is the first example of a CBM that can specifically recognize the side-chain monosaccharides of branched hemicelluloses.

scholarly journals On the distinct binding modes of expansin and carbohydrate-binding module proteins on crystalline and nanofibrous cellulose: implications for cellulose degradation by designer cellulosomes

2018 ◽  
Vol 20 (12) ◽  
pp. 8278-8293 ◽  
Author(s):  
Adam Orłowski ◽  
Lior Artzi ◽  
Pierre-Andre Cazade ◽  
Melissabye Gunnoo ◽  
Edward A. Bayer ◽  
...  
Keyword(s):  
Cellulose Degradation ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Binding Modes ◽  
Special Group ◽  
P Transformation ◽  
Hydrolysis Of

Transformation of cellulose into monosaccharides can be achieved by hydrolysis of the cellulose chains, carried out by a special group of enzymes known as cellulases.

scholarly journals Comparative Analyses of Two Thermophilic Enzymes Exhibiting both β-1,4 Mannosidic and β-1,4 Glucosidic Cleavage Activities from Caldanaerobius polysaccharolyticus

2010 ◽  
Vol 192 (16) ◽  
pp. 4111-4121 ◽  
Author(s):  
Yejun Han ◽  
Dylan Dodd ◽  
Charles W. Hespen ◽  
Samuel Ohene-Adjei ◽  
Charles M. Schroeder ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Biochemical Properties ◽  
Degree Of Polymerization ◽  
Glycoside Hydrolase Family ◽  
Carbohydrate Binding ◽  
Biofuel Industry ◽  
Carbohydrate Binding Modules ◽  
Mannanase Activity ◽  
Hydrolysis Of ◽  
Derivatives Of

ABSTRACT The hydrolysis of polysaccharides containing mannan requires endo-1,4-β-mannanase and 1,4-β-mannosidase activities. In the current report, the biochemical properties of two endo-β-1,4-mannanases (Man5A and Man5B) from Caldanaerobius polysaccharolyticus were studied. Man5A is composed of an N-terminal signal peptide (SP), a catalytic domain, two carbohydrate-binding modules (CBMs), and three surface layer homology (SLH) repeats, whereas Man5B lacks the SP, CBMs, and SLH repeats. To gain insights into how the two glycoside hydrolase family 5 (GH5) enzymes may aid the bacterium in energy acquisition and also the potential application of the two enzymes in the biofuel industry, two derivatives of Man5A (Man5A-TM1 [TM1 stands for truncational mutant 1], which lacks the SP and SLH repeats, and Man5A-TM2, which lacks the SP, CBMs, and SLH repeats) and the wild-type Man5B were biochemically analyzed. The Man5A derivatives displayed endo-1,4-β-mannanase and endo-1,4-β-glucanase activities and hydrolyzed oligosaccharides with a degree of polymerization (DP) of 4 or higher. Man5B exhibited endo-1,4-β-mannanase activity and little endo-1,4-β-glucanase activity; however, this enzyme also exhibited 1,4-β-mannosidase and cellodextrinase activities. Man5A-TM1, compared to either Man5A-TM2 or Man5B, had higher catalytic activity with soluble and insoluble polysaccharides, indicating that the CBMs enhance catalysis of Man5A. Furthermore, Man5A-TM1 acted synergistically with Man5B in the hydrolysis of β-mannan and carboxymethyl cellulose. The versatility of the two enzymes, therefore, makes them a resource for depolymerization of mannan-containing polysaccharides in the biofuel industry. Furthermore, on the basis of the biochemical and genomic data, a molecular mechanism for utilization of mannan-containing nutrients by C. polysaccharolyticus is proposed.

Hydrolysis of softwood by Aspergillus mannanase: Role of a carbohydrate-binding module

2010 ◽  
Vol 148 (4) ◽  
pp. 163-170 ◽  
Author(s):  
Tuan Anh Pham ◽  
Jean Guy Berrin ◽  
Eric Record ◽  
Kim Anh To ◽  
Jean-Claude Sigoillot
Keyword(s):  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Hydrolysis Of

scholarly journals Novel xylan-binding properties of an engineered family 4 carbohydrate-binding module

2007 ◽  
Vol 406 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Lavinia Cicortas Gunnarsson ◽  
Cedric Montanier ◽  
Richard B. Tunnicliffe ◽  
Mike P. Williamson ◽  
Harry J. Gilbert ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Binding Site ◽  
Hydrophobic Interactions ◽  
Molecular Engineering ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Wild Type ◽  
Rhodothermus Marinus ◽  
Binding Properties ◽  
Carbohydrate Binding Modules

Molecular engineering of ligand-binding proteins is commonly used for identification of variants that display novel specificities. Using this approach to introduce novel specificities into CBMs (carbohydrate-binding modules) has not been extensively explored. Here, we report the engineering of a CBM, CBM4-2 from the Rhodothermus marinus xylanase Xyn10A, and the identification of the X-2 variant. As compared with the wild-type protein, this engineered module displays higher specificity for the polysaccharide xylan, and a lower preference for binding xylo-oligomers rather than binding the natural decorated polysaccharide. The mode of binding of X-2 differs from other xylan-specific CBMs in that it only has one aromatic residue in the binding site that can make hydrophobic interactions with the sugar rings of the ligand. The evolution of CBM4-2 has thus generated a xylan-binding module with different binding properties to those displayed by CBMs available in Nature.

Elucidation of the mechanism of interaction between Klebsiella pneumoniae pullulanase and cyclodextrin

2018 ◽  
Vol 74 (11) ◽  
pp. 1115-1123 ◽  
Author(s):  
Naoki Saka ◽  
Hiroyuki Iwamoto ◽  
Dominggus Malle ◽  
Nobuyuki Takahashi ◽  
Kimihiko Mizutani ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Strong Interaction ◽  
Active Site ◽  
Side Chain ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Strong Inhibition ◽  
Hydrophobic Residue ◽  
Active Site Cleft ◽  
Mechanism Of Interaction

Crystal structures of Klebsiella pneumoniae pullulanase (KPP) in complex with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD) and γ-cyclodextrin (γ-CD) were refined at around 1.98–2.59 Å resolution from data collected at SPring-8. In the structures of the complexes obtained with 1 mM α-CD or γ-CD, one molecule of CD was found at carbohydrate-binding module 41 only (CBM41). In the structures of the complexes obtained with 1 mM β-CD or with 10 mM α-CD or γ-CD, two molecules of CD were found at CBM41 and in the active-site cleft, where the hydrophobic residue of Phe746 occupies the inside cavity of the CD rings. In contrast to α-CD and γ-CD, one β-CD molecule was found at the active site only in the presence of 0.1 mM β-CD. These results were coincident with the solution experiments, which showed that β-CD inhibits this enzyme more than a thousand times more potently than α-CD and γ-CD. The strong inhibition of β-CD is caused by the optimized interaction between β-CD and the side chain of Phe746. The increased K i values of the F746A mutant for β-CD supported the importance of Phe746 in the strong interaction of pullulanase with β-CD.

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