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	Gage Lab Group Research Projects Research Projects Intrinsically Disordered Proteins The prevailing dogma in protein science has always been that structure equals function. However, it is now accepted that a large number of proteins, referred to as Intrinsically Disordered Proteins (IDPs), are actually functional in the absence of measurable structure. A key property of these proteins is that they contain more charged and fewer hydrophobic amino acids than traditional globular proteins, which promotes the disordered state. My lab has been interested over the past year with understanding the relationship between sequence and the degree of disorder in homologous IDPs. The majority of experimentally characterized IDPs are not related and it has generally been assumed that all homologous IDPs exhibit similar disordered characteristics. However, our work is providing experimental evidence that this is not true and we have been using the flagella regulatory protein FlgM to determine the relationship between amino acid sequence and degree of disorder. In addition, we have discovered a thermophilic FlgM gene that exhibits temperature-dependent folding and we are expanding our studies to determine if this is a general property of thermophilic IDPs. Design of novel antimicrobial agents Undeniably, the emergence of drug-resistant organisms is an increasing threat, not only to the United States, but to the entire world population. According to the CDC, 1 in 8 infections contracted in U.S. hospitals are from enterococci, 30% of which are resistant to vancomycin, the major antimicrobial agent used to treat enterococci infection. In addition, the most commonly contracted bacterial infection in hospitals is Staphylococcus aureus; methicillin resistant S. aureus (MRSA) accounts for 64% of healthcare associated staphylococcal infections in 2004, compared to 2% in 1974. MRSA infections are not limited to hospitals, but can originate in schools, gyms and a variety of other sources as well. Approximately 94,000 people contract invasive MRSA infections annually, leading to 19,000 deaths. As with enterococcal infections, one of the primary antimicrobial agents used to treat MRSA infections is vancomycin, but there are now reports of vancomycin resistant strains of S. aureus as well, demonstrating that the trend towards antimicrobial resistance is clearly increasing. Development of new antimicrobial agents is needed now more than ever to combat hospital-acquired infections in developed and developing countries, rising rates of life-threatening conditions including pneumonia and tuberculosis, as well as the demands of microbial biological warfare. Even as antimicrobial agent resistance and microbial warfare has emerged as a medical research priority, there remains a dearth of new antimicrobial agents in recent years. When examined closely, recent advances in antimicrobial agent development fall within a very narrow scope. The common approach of combating resistance using small changes to existing drugs or targeting established, effective bacterial functions (such as cell wall biosynthesis, protein biosynthesis, or DNA replication/repair mechanisms), while effective in minimizing the time to FDA approval, results in increased rates of resistance acquisition. My lab has identified a series of previously untargeted enzymes that show promise as targets for novel antimicrobial agents. We are working in collaboration with Dr. Cindy Browder's laboratory to design and synthesize inhibitors to these enzymes using a rational design approach. Our initial compounds show promise as enzyme inhibitors and we have begun testing the biological activity of these complexes. Protein conformational changes We have recently begun a series of experiments in collaboration with Bill Montfort at the University of Arizona to elucidate the conformational changes associated with regulation of soluble guanylyl/guanylate cyclase (sGC) by nitric oxide (NO). NO is a signaling molecule influencing diverse biology, including tumor growth, tissue development, immune response, blood pressure, neural function, cell growth and cell death. Binding of NO stimulates the catalytic activity of sGC several hundred fold via a putative conformational change but the nature of this conformational changes remains poorly understood. Several synthetic compounds have been discovered that stimulate sGC and, importantly, some of these, including YC-1 and BAY 41-2272, do so independently of NO through binding to a site distinct from the heme and catalytic sites. We have been using these compounds in conjunction with a series of biophysical techniques to investigate the conformational changes associated with sGC activation.

Gage Lab Group Research Projects

Research Projects

Intrinsically Disordered Proteins

The prevailing dogma in protein science has always been that structure equals function. However, it is now accepted that a large number of proteins, referred to as Intrinsically Disordered Proteins (IDPs), are actually functional in the absence of measurable structure. A key property of these proteins is that they contain more charged and fewer hydrophobic amino acids than traditional globular proteins, which promotes the disordered state. My lab has been interested over the past year with understanding the relationship between sequence and the degree of disorder in homologous IDPs. The majority of experimentally characterized IDPs are not related and it has generally been assumed that all homologous IDPs exhibit similar disordered characteristics. However, our work is providing experimental evidence that this is not true and we have been using the flagella regulatory protein FlgM to determine the relationship between amino acid sequence and degree of disorder. In addition, we have discovered a thermophilic FlgM gene that exhibits temperature-dependent folding and we are expanding our studies to determine if this is a general property of thermophilic IDPs.

Design of novel antimicrobial agents

Undeniably, the emergence of drug-resistant organisms is an increasing threat, not only to the United States, but to the entire world population. According to the CDC, 1 in 8 infections contracted in U.S. hospitals are from enterococci, 30% of which are resistant to vancomycin, the major antimicrobial agent used to treat enterococci infection. In addition, the most commonly contracted bacterial infection in hospitals is Staphylococcus aureus; methicillin resistant S. aureus (MRSA) accounts for 64% of healthcare associated staphylococcal infections in 2004, compared to 2% in 1974. MRSA infections are not limited to hospitals, but can originate in schools, gyms and a variety of other sources as well. Approximately 94,000 people contract invasive MRSA infections annually, leading to 19,000 deaths. As with enterococcal infections, one of the primary antimicrobial agents used to treat MRSA infections is vancomycin, but there are now reports of vancomycin resistant strains of S. aureus as well, demonstrating that the trend towards antimicrobial resistance is clearly increasing.

Development of new antimicrobial agents is needed now more than ever to combat hospital-acquired infections in developed and developing countries, rising rates of life-threatening conditions including pneumonia and tuberculosis, as well as the demands of microbial biological warfare. Even as antimicrobial agent resistance and microbial warfare has emerged as a medical research priority, there remains a dearth of new antimicrobial agents in recent years. When examined closely, recent advances in antimicrobial agent development fall within a very narrow scope. The common approach of combating resistance using small changes to existing drugs or targeting established, effective bacterial functions (such as cell wall biosynthesis, protein biosynthesis, or DNA replication/repair mechanisms), while effective in minimizing the time to FDA approval, results in increased rates of resistance acquisition.

My lab has identified a series of previously untargeted enzymes that show promise as targets for novel antimicrobial agents. We are working in collaboration with Dr. Cindy Browder's laboratory to design and synthesize inhibitors to these enzymes using a rational design approach. Our initial compounds show promise as enzyme inhibitors and we have begun testing the biological activity of these complexes.

Protein conformational changes

We have recently begun a series of experiments in collaboration with Bill Montfort at the University of Arizona to elucidate the conformational changes associated with regulation of soluble guanylyl/guanylate cyclase (sGC) by nitric oxide (NO). NO is a signaling molecule influencing diverse biology, including tumor growth, tissue development, immune response, blood pressure, neural function, cell growth and cell death. Binding of NO stimulates the catalytic activity of sGC several hundred fold via a putative conformational change but the nature of this conformational changes remains poorly understood. Several synthetic compounds have been discovered that stimulate sGC and, importantly, some of these, including YC-1 and BAY 41-2272, do so independently of NO through binding to a site distinct from the heme and catalytic sites. We have been using these compounds in conjunction with a series of biophysical techniques to investigate the conformational changes associated with sGC activation.

Last updated on April 20, 2010