Carbohydrate Recognition Model

The small size of hevein (43 residues), and the ease of its availability by biochemical purification or methods of peptide synthesis make this domain an excellent model system for the study of carbohydrate recognition by proteins. Herein, and taking the hevein domain as a model, we focus on the study of those molecular-recognition features relevant for the interactions between carbohydrates and proteins. We detail all of the techniques that are instrumental for tackling this problem, and how these can strategically be combined in an efficient manner. Particular emphasis is placed on the acquisition and analysis of data at atomic resolution (by NMR and/or X-ray ), and how these structural data relate with thermodynamic and kinetic information in reaching an understanding of the forces and interactions that play decisive roles in the interactions between carbohydrates and proteins. 

Carbohydrates, Recognition of, p. 169 Carbonic Anhydrase Models, p. 178 Carcerands and Hernicarcerands. p. 189 Cation-n Interactions, p. 214 Cavitands, p. 219 Chiral Guest Recognition, p. 236 Classical Descriptions of Inclusion Compounds, p. 253 Classification and Nomenclature of Supramolecular Compounds, p. 261 Clathrate Hydrates, p. 274 Conzplexation of Fullerenes, p. 302 Concepts in Ciystal Engineering, p. 319 Crown Ethers, p. 326 Cryptands, p. 334 Cryptophanes, p. 340 Cyclodextrins, p. 398... 

The levels of j8-D-2-acetamido-deoxyglucosidase activity in skin fibroblasts from cases of cystic fibrosis and controls have been compared. In a study of I-cell disease (mucolipidosis II) a model has been presented for the structure of the carbohydrate recognition site of fibroblast-derived )3-D-2-acetamido-2-deoxyhexosidase that may extend to the other affected hydrolases and that is responsible for specific uptake of the enzyme by fibroblasts. ... 

Whereas a wealth of structural information derived from x-ray and NMR spectroscopy[9, 11, 12], is available for Types 1 and III AFPs, very little is known about the three dimensional structure of the largest, Type II AFP and Type IV. A three dimensional structure of Type II antifreeze protein was recently proposed using comparative modeling[13]. This structure was derived using a sequence similarity to the carbohydrate recognition domain (CDR) of... 

B. Mukhopadhyay, M. B. Martins, R. Karamanska, D. A. Russell, and R. A. Field, Bacterial detection using carbohydrate-functionalised CdS quantum dots A model study exploiting E. coli recognition of mannosides, Tetrahedron Lett., 50 (2009) 886-889. 

The molecular recognition of septanose carbohydrates has been investigated in depth by using concanavalin A68 as a model lectin. Complex formation was analysed by STD experiments and showed the first direct evidence of binding, by a natural protein, for this class of ring-expanded carbohydrate molecules. 

Abstract Carbohydrates have been investigated and developed as delivery vehicles for shuttling nucleic acids into cells. In this review, we present the state of the art in carbohydrate-based polymeric vehicles for nucleic acid delivery, with the focus on the recent successes in preclinical models, both in vitro and in vivo. Polymeric scaffolds based on the natural polysaccharides chitosan, hyaluronan, pullulan, dextran, and schizophyllan each have unique properties and potential for modification, and these results are discussed with the focus on facile synthetic routes and favorable performance in biological systems. Many of these carbohydrates have been used to develop alternative types of biomaterials for nucleic acid delivery to typical polyplexes, and these novel materials are discussed. Also presented are polymeric vehicles that incorporate copolymerized carbohydrates into polymer backbones based on polyethylenimine and polylysine and their effect on transfection and biocompatibility. Unique scaffolds, such as clusters and polymers based on cyclodextrin (CD), are also discussed, with the focus on recent successes in vivo and in the clinic. These results are presented with the emphasis on the role of carbohydrate and charge on transfection. Use of carbohydrates as molecular recognition ligands for cell-type specific dehvery is also briefly... 

Several laboratories have studied the assimilation of specific lysosomal enzymes using as model systems skin fibroblasts deficient in the enzyme under study. The underlying mechanism for the translocation of lysosomal enzymes was hypothesized to involve binding of carbohydrate-containing recognition markers to specific cell surface receptors (1 5). In support of this hypothesis Hickman, Shapiro, and Neufeld (16J found that treatment of N-acetyl-B-hexosaminidase with periodate under conditions that dTd not affect enzymatic activity prevented the efficient assimilation of this enzyme by Sandhoff fibroblasts. Additionally, Kresse and von Figura (1 7) found that treatment of f -acetyl-a-hexosaminidase with B-galactosidase reduced the assimilation of this enzyme by San-filippo B fibroblasts. 

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