Mutational Analysis Provides Molecular Insight into the Carbohydrate-Binding Region of Calreticulin:  Pivotal Roles of Tyrosine-109 and Aspartate-135 in Carbohydrate Recognition†

Biochemistry ◽  
2004 ◽  
Vol 43 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Mili Kapoor ◽  
Lars Ellgaard ◽  
Jayashree Gopalakrishnapai ◽  
Christiane Schirra ◽  
Emiliano Gemma ◽  
...  
Keyword(s):  
Mutational Analysis ◽  
Carbohydrate Binding ◽  
Binding Region ◽  
Carbohydrate Recognition ◽  
Insight Into

Genomic analysis of C-type lectins

2002 ◽  
Vol 69 ◽  
pp. 59-72 ◽  
Author(s):  
Kurt Drickamer ◽  
Andrew J. Fadden
Keyword(s):  
Biological Effects ◽  
Cell Signalling ◽  
Genomic Analysis ◽  
Binding Activity ◽  
Immunoglobulin Superfamily ◽  
Carbohydrate Binding ◽  
Carbohydrate Recognition ◽  
Calcium Dependent ◽  
Binding Domains ◽  
Carbohydrate Recognition Domains

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.

scholarly journals Deamidation and glycation of a Bacillus licheniformis α-amylase during industrial fermentation can improve detergent wash performance

Amylase ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 38-49
Author(s):  
Connie Pontoppidan ◽  
Svend G. Kaasgaard ◽  
Carsten P. Sønksen ◽  
Carsten Andersen ◽  
Birte Svensson
Keyword(s):  
Bacillus Licheniformis ◽  
Mutational Analysis ◽  
Peptide Mapping ◽  
Substrate Binding ◽  
Carbohydrate Binding ◽  
Surface Binding ◽  
Lysine Residues ◽  
Tandem Mass Spectrometric ◽  
Binding Cleft ◽  
Household Detergents

Abstract The industrial thermostable Bacillus licheniformis α-amylase (BLA) has wide applications, including in household detergents, and efforts to improve its performance are continuously ongoing. BLA during the industrial production is deamidated and glycated resulting in multiple forms with different isoelectric points. Forty modified positions were identified by tandem mass spectrometric peptide mapping of BLA forms separated by isoelectric focusing. These modified 12 asparagine, 9 glutamine, 8 arginine and 11 lysine residues are mostly situated on the enzyme surface and several belong to regions involved in stability, activity and carbohydrate binding. Eight residues presumed to interact with starch at the active site and surface binding sites (SBSs) were subjected to mutational analysis. Five mutants mimicking deamidation (N→D, Q→E) at the substrate binding cleft showed moderate to no effect on thermostability and k cat and K M for maltoheptaose and amylose. Notably, the mutations improved laundry wash efficiency in detergents at pH 8.5 and 10.0. Replacing three reducing sugar reactive side chains (K→M, R→L) at a distant substrate binding region and two SBSs enhanced wash performance especially in liquid detergent at pH 8.5, slightly improved enzymatic activity and maintained thermostability. Wash performance was most improved (5-fold) for the N265D mutant near substrate binding subsite +3.

scholarly journals Amino-sugars enhance recognition and phagocytosis of particles by human neutrophils

Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 697-701 ◽  
Author(s):  
RL Doolittle ◽  
CH Packman ◽  
MA Lichtman
Keyword(s):  
Human Neutrophils ◽  
Amino Sugars ◽  
Carbohydrate Binding ◽  
Carbohydrate Recognition ◽  
Membrane Structures ◽  
Fluorescent Beads ◽  
Amino Derivatives ◽  
Recognition Systems ◽  
Dose Dependent ◽  
Derivatives Of

Abstract Neutrophils were examined for their ability to recognize and ingest beads coated with amino-derivatives of glucose, mannose, and galactose. Radioactive or fluorescent beads coated with any of the three sugars were ingested to an extent three times that observed with albumin- coated beads. Enhancement of ingestion of sugar-coated beads was much more evident when examined by electron micrographic studies. Inclusion of glucose or mannose in the medium with glucose- or mannose-coated beads caused a dose-dependent reduction of ingestion to control levels, but ingestion of galactose-coated beads was poorly inhibited. Similarly, galactose or fucose (6-deoxy-galactose) markedly inhibited ingestion of galactose-coated beads, but caused only a slight decrease in ingestion of glucose- or mannose-coated beads. Thus, neutrophils possess carbohydrate-binding membrane structures that can mediate recognition and ingestion of sugar-coated beads. Such carbohydrate recognition systems may underlie certain interactions of neutrophils and other surfaces.

scholarly journals Protein-observed 19F NMR of LecA from Pseudomonas aeruginosa

Glycobiology ◽  
2020 ◽  
Author(s):  
Elena Shanina ◽  
Eike Siebs ◽  
Hengxi Zhang ◽  
Daniel Varón Silva ◽  
Ines Joachim ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Carbohydrate Binding ◽  
Binding Region ◽  
Chronic Infections ◽  
Nmr Titration ◽  
Affinity Ligands ◽  
Natural Ligands ◽  
Future Drug

Abstract The carbohydrate-binding protein LecA (PA-IL) from Pseudomonas aeruginosa plays an important role in the formation of biofilms in chronic infections. Development of inhibitors to disrupt LecA-mediated biofilms is desired but it is limited to carbohydrate-based ligands. Moreover, discovery of drug-like ligands for LecA is challenging because of its weak affinities. Therefore, we established a protein-observed 19F (PrOF) nuclear magnetic resonance (NMR) to probe ligand binding to LecA. LecA was labeled with 5-fluoroindole to incorporate 5-fluorotryptophanes and the resonances were assigned by site-directed mutagenesis. This incorporation did not disrupt LecA preference for natural ligands, Ca2+ and d-galactose. Following NMR perturbation of W42, which is located in the carbohydrate-binding region of LecA, allowed to monitor binding of low-affinity ligands such as N-acetyl d-galactosamine (d-GalNAc, Kd = 780 ± 97 μM). Moreover, PrOF NMR titration with glycomimetic of LecA p-nitrophenyl β-d-galactoside (pNPGal, Kd = 54 ± 6 μM) demonstrated a 6-fold improved binding of d-Gal proving this approach to be valuable for ligand design in future drug discovery campaigns that aim to generate inhibitors of LecA.

scholarly journals Structural insight into industrially relevant glucoamylases: flexible positions of starch-binding domains

2018 ◽  
Vol 74 (5) ◽  
pp. 463-470 ◽  
Author(s):  
Christian Roth ◽  
Olga V. Moroz ◽  
Antonio Ariza ◽  
Lars K. Skov ◽  
Keiichi Ayabe ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Relative Concentration ◽  
Spatial Arrangement ◽  
Carbohydrate Binding ◽  
Polymeric Substrate ◽  
Binding Domains ◽  
Catalytic Mechanisms ◽  
The Individual ◽  
First Time ◽  
Insight Into

Glucoamylases are one of the most important classes of enzymes in the industrial degradation of starch biomass. They consist of a catalytic domain and a carbohydrate-binding domain (CBM), with the latter being important for the interaction with the polymeric substrate. Whereas the catalytic mechanisms and structures of the individual domains are well known, the spatial arrangement of the domains with respect to each other and its influence on activity are not fully understood. Here, the structures of three industrially used fungal glucoamylases, two of which are full length, have been crystallized and determined. It is shown for the first time that the relative orientation between the CBM and the catalytic domain is flexible, as they can adopt different orientations independently of ligand binding, suggesting a role as an anchor to increase the contact time and the relative concentration of substrate near the active site. The flexibility in the orientations of the two domains presented a considerable challenge for the crystallization of the enzymes.

Solvent Effects in Carbohydrate Binding by Synthetic Receptors: Implications for the Role of Water in Natural Carbohydrate Recognition

2008 ◽  
Vol 120 (14) ◽  
pp. 2733-2736 ◽  
Author(s):  
Emmanuel Klein ◽  
Yann Ferrand ◽  
Nicholas P. Barwell ◽  
Anthony P. Davis
Keyword(s):  
Solvent Effects ◽  
Carbohydrate Binding ◽  
Synthetic Receptors ◽  
Carbohydrate Recognition
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