Aug
12
Mon
2013
Dr. Lee Hartwell Session @ Amriteshwari Hall
Aug 12 @ 8:15 pm – 9:15 pm
LeeHartwellLeland H. Hartwell Ph.D.
2001 Nobel Laureate, Physiology & Medicine

Dr. Lee Hartwell received the 2001 Nobel Prize in Physiology / Medicine for his discovery of protein molecules that control the division of cells. He was the President and Director of the Fred Hutchinson Cancer Research Center in Seattle, Washington before moving to Arizona State University’s Center for Sustainable Health.

Dr. Hartwell is also adjunct faculty at Amrita University. He spoke to the delegates at Bioquest from his office in the US, over Amrita’s e-learning platform A-View. Given below are excerpts from his address.

I would like to address the young people in the audience. I know that many of you may have come to this meeting wondering, “How can I become a successful scientist? How can I prepare myself to make a contribution in this world?”

These questions are interesting to me also.

Believe it or not, I am still trying to be a successful scientist. That may surprise you since you probably think that a Nobel laureate must have found the answers. But the problem is that the answers to these questions change with time and the answers are different today than what they were when I began my career fifty years ago. The strategy of the 1960’s doesn’t work so well anymore. What is different now?

First, what we know now is much more. For example, by 1970, no genes from any organisms were sequenced. In 2013, we have the complete sequence of the human genome. Second, not only do we know much more today, accessing that knowledge is easy. Third, obtaining new information is much faster today.

Our rich understanding of science and technology is now needed to solve many serious problems. The human population has reached the size where we are utilizing all available resource of the planet. We are utilizing all of the agricultural land, all of the water, all of the forest and fishing resources. We are also polluting the planet that we live on.

We are polluting the land with fertilizers and pesticides; the oceans with acids and the atmosphere with carbon dioxide. We are using up top soil and ground water, thereby reducing our capacity to feed ourselves. We are using up petroleum, the energy source that our entire economy is dependent on. These are problems we were largely unaware of, fifty years ago. But these are problems that must be solved in your life times.

The big question facing your generation is, how can human beings live sustainably on planet earth. Your two broad goals on sustainability are 1) leave the planet as you first found it for your future generations; don’t use up the resources and don’t pollute the planet 2) everyone deserves to have an equal share of the earth’s resources.

Income strongly determines one’s opportunities in life. Many poor people succumb to chronic diseases and unhealthy environments. This inequality undermines our ability to live sustainably. We can’t ask the poor to leave the planet as they found it if they can’t support their families. Education, healthcare, employment are essential to having a sustainable society.

How can we be a successful scientist in 2013?
1. First choose a problem to solve
2. Ask questions to understand why it is not solved
3. Collaborate with those who can help
4. Develop a solution that works in the real world

Chronic diseases are our major burden and this burden will get worse. Heart disease, diabetes, cancer, dementia and other diseases. The good news is that the chronic diseases are largely preventable and more easily curable if detected early. One question that attracts me is how can we detect disease earlier when it can be more easily cured?

Can we use our increasing knowledge in molecular biology to identify biomarkers for early disease detection?

We need to collaborate very closely with clinicians who care for patients to find out exactly where they need help.

I think if we apply our technology to important clinical questions we will actually save medical expenditure and be well on our way to making a great contribution to society.

 

Aug
13
Tue
2013
Invited Talk: A cost-effective approach to Protein Structure-guided Drug Discovery: Aided by Bioinformatics, Chemoinformatics and computational chemistry @ Sathyam Hall
Aug 13 @ 11:15 am – 11:40 am

kalKal Ramnarayan, Ph.D.
Co-founder President & Chief Scientific Officer, Sapient Discovery, San Diego, CA, USA


A cost-effective approach to Protein Structure-guided Drug Discovery: Aided by Bioinformatics, Chemoinformatics and computational chemistry

With the mapping of the human genome completed almost a decade ago, efforts are still underway to understand the gene products (i.e., proteins) in the human biological and disease pathways.  Deciphering such information is very important for the discovery and development of small molecule drugs as well as protein therapeutics for various human diseases for which no cure exists.  As an example, with more than 500 members, the kinase family of protein targets continues to be an important and attractive class for drug discovery.  While how many of the members in this family are actually druggable is still to be established, there are several ongoing efforts on this class of proteins across a broad spectrum of disease categories.  Even though in general the protein structural topology might looks similar, there are issues with respect selectivity of identified small molecule inhibitors when, the lead molecule discovery is carried out at the ATP binding site.  As an added complexity, allosteric modulators are needed for some of the members, but the actual site for such modulation on the protein target can not resolved with uncertainty.  In this presentation we will describe a bioinformatics and computational based platform for small molecule discovery for protein targets that are involved in protein-protein interactions as well as targets like kinases and phosphatases.  We will describe a computational approach in which we have used an informatics based platform with several hundred kinases to sort through in silico and identify inhibitors that are likely to be highly selective in the lead generation phase.  We will discuss the implication of this approach on the drug discovery of the kinase and phosphatase classes in general and independent of the disease category.

 

Invited Talk: Pertubation of DNA topology in mycobacteria @ Acharya Hall
Aug 13 @ 11:50 am – 12:12 pm

NagarajaV. Nagaraja Ph.D.
Professor, Indian Institute of Science, Bengaluru, India


Perturbation of DNA topology in mycobacteria

To maintain the topological homeostasis of the genome in the cell, DNA topoisomerases catalyse DNA cleavage, strand passage and rejoining of the ends. Thus, although they are essential house- keeping enzymes, they are the most vulnerable targets; arrest of the reaction after the first trans-esterification step leads to breaks in DNA and cell death.  Some of the successful antibacterial or anticancer drugs target the step ie arrest the reaction or stabilize the topo -DNA covalent complex. I will describe our efforts in this direction – to target DNA gyrase and also topoisomerase1 from mycobacteria. The latter, although essential, has no inhibitors described so far. The new inhibitors being characterized are also used to probe topoisomerase control of gene expression.

In the biological warfare between the organisms, a diverse set of molecules encoded by invading genomes target the above mentioned most vulnerable step of topoisomerase  reaction, leading to the accumulation of double strand breaks. Bacteria, on their part appear to have developed defense strategies to protect the cells from genomic double strand breaks. I will describe a mechanism involving three distinct gyrase interacting proteins which inhibit the enzyme in vitro. However, in vivo all these topology modulators protect DNA gyrase from poisoning effect by sequestering the enzyme away from DNA.

Next, we have targeted a topology modulator protein, a nucleoid associated protein(NAP) from Mycobacterium tuberculosis to develop small molecule inhibitors by structure based design. Over expression of HU leads to alteration in the nucleoid architecture. The crystal structure of the N-terminal half of HU reveals a cleft that accommodates duplex DNA. Based on the structural feature, we have designed inhibitors which bind to the protein and affect its interaction with DNA, de-compact the nucleoid and inhibit cell growth. Chemical probing with the inhibitors reveal the importance of HU regulon in M.tuberculosis.

Aug
14
Wed
2013
Delegate Talk: Intrinsic modulation of cytokine response by mycobacteria @ Acharya Hall
Aug 14 @ 11:35 am – 11:45 am
Delegate Talk: Intrinsic modulation of cytokine response by mycobacteria @ Acharya Hall | Vallikavu | Kerala | India

Sukhithasri V, Nisha N, Vivek V and Raja Biswas


The host innate immune system acts as the first line of defense against invading pathogens. During an infection, the host innate immune cells recognize unique conserved molecules on the pathogen known as Pathogen Associated Molecular Patterns (PAMPs). This recognition of PAMPs helps the host mount an innate immune response leading to the production of cytokines (Akira et al. 2006). Peptidoglycan, one of the most conserved and essential component of the bacterial cell wall is one such PAMP. Peptidoglycan is known to have potent proinflammatory properties (Gust et al. 2007). Host recognize peptidoglycan using Nucleotide oligomerization domain proteins (NODs). This recognition of peptidoglycan activates the NODs and triggers downstream signaling leading to the nuclear translocation of NF-κB and production of cytokines (McDonald et al. 2005). Pathogenic bacteria modify their peptidoglycan as a strategy to evade innate immune recognition, which helps it to establish infection in the host. These peptidoglycan modifications include O-acetylation and N-glycolylation of muramic acid and N-deacetylation of N-acetylglucosamine (Davis et al. 2011). Modification of mycobacterial peptidoglycan by N-glycolylation prevents the catalytic activity of lysozyme (Raymond et al. 2005). Additionally, mycobacterial peptidoglycan is modified by amidation for unknown reasons.

Here, we have investigated the role of amidated peptidoglycan in Mycobacterium sp in modulating the innate immune response. We isolated amidated peptidoglycan from Mycobacterium sp and non-amidated peptidoglycan from Escherichia coli. We made a comparative analysis of the cytokine response produced on stimulation of innate immune cells by peptidoglycan from E. Coli and Mycobacterium sp. Macrophages and whole blood were treated with peptidoglycan and the cytokines secreted into spent medium and plasma respectively were analyzed using ELISA. Our results show that peptidoglycan from Mycobacterium sp is less effective in stimulating innate immune cells to produce cytokines. This intrinsic modulation of the cytokine response suggests that mycobacteria modify their peptidoglycan by amidation to evade innate immune response.