Proteoglycans major components of the extracellular matrix, bind a vast array of proteins that regulate diverse biological processes. Heparan sulfate is one of the important proteoglycans found in the extracellular matrix. Past studies have focused on heparin, a related glycosaminoglycan widely used as a drug and available in large quantities. Heparin and heparan sulfate glycosaminoglycans have many of the same structural features and bind a number of proteins that are found in the extracellular matrix including vitronectin and fibroblast growth factors. Clearly, binding of acidic polysaccharides to proteins is a common biological event that may have very important consequences. Unfortunately, the primary structural requirements, for either protein or oligosaccharide, that give rise to this binding are largely unknown. Molecular modeling and some experimental data predict that heparin-binding proteins contain specific patterns of basic amino acids (consensus sequences) with high affinity for acidic oligosaccharides. Nevertheless, these requirements are only now being studied and the oligosaccharide requirements for binding to protein or peptide have not been reported. This study will examine the hypothesis that certain oligosaccharide sequences in heparin and heparan sulfate have high affinity for consensus peptide sequences in proteins present in the extracellular matrix. A variety of peptides based on sequences in acidic fibroblast growth factor and vitronectin, predicted to have high affinity for oligosaccharide, will be synthesized. These peptides will be used to isolate high affinity oligosaccharides, which will be examined for composition and sequence. Oligosaccharide-peptide interactions will be examined for: l. binding affinity (Kd): 2. binding specificity; 3. binding thermodynamics; 4. binding orientation; and 5. binding site structural requirements. Peptides will also be synthesized to contain variations of the consensus sequence and modified oligosaccharides will be synthesized to help establish the structure activity relationship for oligosaccharide-peptide interaction. Native protein will be compared with synthetic peptide to confirm specificity of binding. Vitronectin and recombinant acidic fibroblast growth factor are the proteins to be studied because of the important biological consequences of their binding to heparin/heparan sulfate. Ultimately, these studies should lead to custom designed specific oligosaccharide molecules that have increased protein binding affinity and custom designed peptides that have increased oligosaccharide binding affinity to enhance or attenuate the activities associated with oligosaccharide-protein interaction. These oligosaccharides and peptides represent the starting point for new drug design focused on peptido- mimetics and sulfated oligosaccharide-mimetics. Such new therapeutic agents might be used to regulate a variety of biological processes including angiogenesis, metastasis, atherogenesis, immune responses, HIV infection, and thrombosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL052622-02
Application #
2332527
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
1996-02-01
Project End
2001-01-31
Budget Start
1997-02-01
Budget End
1998-01-31
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Iowa
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Guerrini, Marco; Beccati, Daniela; Shriver, Zachary et al. (2008) Oversulfated chondroitin sulfate is a contaminant in heparin associated with adverse clinical events. Nat Biotechnol 26:669-75
Copeland, Ronald; Balasubramaniam, Arun; Tiwari, Vaibhav et al. (2008) Using a 3-O-sulfated heparin octasaccharide to inhibit the entry of herpes simplex virus type 1. Biochemistry 47:5774-83
Garg, Hari G; Mrabat, Hicham; Yu, Lunyin et al. (2008) Significance of the 2-O-sulfo group of L-iduronic acid residues in heparin on the growth inhibition of bovine pulmonary artery smooth muscle cells. Carbohydr Res 343:2406-10
Zhang, Zhenqing; McCallum, Scott A; Xie, Jin et al. (2008) Solution structures of chemoenzymatically synthesized heparin and its precursors. J Am Chem Soc 130:12998-3007
Warda, Mohamad; Zhang, Fuming; Radwan, Moustafa et al. (2008) Is human placenta proteoglycan remodeling involved in pre-eclampsia? Glycoconj J 25:441-50
Murugesan, Saravanababu; Xie, Jin; Linhardt, Robert J (2008) Immobilization of heparin: approaches and applications. Curr Top Med Chem 8:80-100
Bhattacharyya, Sumit; Gill, Ravinder; Chen, Mei Ling et al. (2008) Toll-like receptor 4 mediates induction of the Bcl10-NFkappaB-interleukin-8 inflammatory pathway by carrageenan in human intestinal epithelial cells. J Biol Chem 283:10550-8
Zhang, Zhenqing; Weiwer, Michel; Li, Boyangzi et al. (2008) Oversulfated chondroitin sulfate: impact of a heparin impurity, associated with adverse clinical events, on low-molecular-weight heparin preparation. J Med Chem 51:5498-501
Ma, Qing; Tobu, Mahmut; Schultz, Christopher et al. (2007) Molecular weight dependent tissue factor pathway inhibitor release by heparin and heparin oligosaccharides. Thromb Res 119:653-61
Ma, Qing; Cornelli, Umberto; Hanin, Israel et al. (2007) Heparin oligosaccharides as potential therapeutic agents in senile dementia. Curr Pharm Des 13:1607-16

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