COMPUTER ASSISTED STRUCTURAL CHARACTERIZATION OF OLIGOSACCHARIDES

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The specific aim of this project is to develop computer-assisted methods for structural characterization of oligosaccharides. This project has focused on developing a World Wide Web (WWW)-based database system for analytical information processing and classification called the Complex Carbohydrate Research Center-Neural Network (CCRC-Net) system. CCRC-Net is designed so that scientists can submit a spectrum of a carbohydrate for identification using the CCRC's patented pattern recognition technology to compare the submitted spectrum to those in the database(s). From the "query spectrum" CCRC-Net produces a "results page" giving a "hit list" of those carbohydrates identical to or most closely resembling the attributes of the query spectrum. Links have been established between CCRC-Net and the Complex Carbohydrate Structure Database (CCSD) and its CarbBank search program. The CCSD/CarbBank now resides on the CCRC's Web site and will also be functionally integrated on the Web with other biosequence and informatic databases such as Medline. The CCRC-Net provides scientists access to a group of databases and their artificial neural network search engines for spectral classification and compound identification of carbohydrates. CCRC-Net is a client-server system that is computer platform-independent. The only requirement is that the user have a graphical Web browser (e.g., Netscape, Microsoft's Internet Explorer, Mosaic). CCRC-Net is designed in a "fractal parallel distributed" manner so that the system can accommodate expansion at any level without compromising its performance in a manner that is completely transparent to the user. Therefore, it is a "distributed" system whose modules, data, or services could reside anywhere in the world. CCRC-Net currently has six databases and six artificial neural network search engines (one for each database) available via the WWW. The six databases contain (i) combined gas chromatography-electron impact mass spectra of partially methylated alditol acetates (GC-EIMS of PMAAs), (ii) 1H-NMR (proton nuclear magnetic resonance) spectra of xyloglucan oligosaccharide residues, (iii and iv) a large (67 structures) and a small (23 structures) group of 1H-NMR spectra of the N-linked oligosaccharide side chains of glycoproteins, (v) 1H-NMR spectra of glucuronoxylomannans (GXMs) from Cryptococcus neoformans, and (vi) gas chromatography-electrospray ionization mass spectra (GC-EIMS) of partially methylated anhydroalditols generated by reductive cleavage of complex carbohydrates. CCRC-Net's restructured graphical user interface utilizes JAVA applets for more intuitive interaction for users. One-button clicks on such tasks as local directory browsing and file transfer provide streamlined acces s to these functions. CCRC-Net also has a JAVA spectrum viewer. The goal of this project is to build the fractal infrastructure (backbone) of CCRC-Net. New databases (virtual data modules, VDM) and search engines (virtual search modules, VSM) plug into the backbone (software infrastructure) which in turn provides connectivity between the new module and other CCRC-Net modules. A manuscript describing this work is being prepared.