With DNA (RNA) and proteins, two major biopolymers, major scientific effort has been aimed at understanding how sequence dictates function. The third major biopolymer is the polysaccharides. One of the most important groups of polysaccharides, in term of its influence on important biological phenomena, are the heparin-like glycosaminoglycans (HLGAGs). HLGAGs are intimately involved in important processes like embryo development, blood clotting, and new vessel growth. We know that HLGAGs bind to proteins and affect their activity, thus influencing cell functions but we do not know how HLGAGs carry out their important biological functions. Part of the problem is that HLGAGs are complicated molecules, more complicated, in terms of their chemical structure, than either DNA or proteins. For instance, while a DNA molecule made of four bases can have 16 possible sequences and a four amino acid peptide can have 160,000 possible sequences, a HLGAG made of four units can potentially have over one million possible sequences! As such, there is a great deal of difficulty, at the present time, in handling the chemical complexity of HLGAGs, especially since there are a lack of tools to isolate pure HLGAGs and determine their structure. Ongoing research in our laboratory is aimed at developing such tools, both to develop a scientific understanding of how HLGAG structure impinges on function, and provide information on novel targets fir intervention in diseases, such as tumor growth, metastasis, and angiogenesis. Recently, we have developed a technique to rapidly determine the chemical sequence of biologically relevant HLGAG polysaccharides. In this grant application, we propose to extend our sequencing procedure to complete isolation and sequencing of active HLGAG fragments directly on a chip. We call our process CAN- MS, which stands for Chip Non-covalent Association Mass Spectrometry. Coupling of several methods into one procedure will allow us to study quickly and efficiently HLGAGs with important biological activities and can lend itself to development of a high throughput, automated machine to answer important scientific questions. One specific question that we propose to address is the HLGAG sequence that binds to and promotes the activity of endostatin, a potent endogenous anti-cancer agent. Similar technologies for DNA and proteins include things like gene chips that have revolutionized the study of these molecules. We hope advancements, like out technology, will do the same thing for HLGAGs.
Showing the most recent 10 out of 14 publications
