Another Successful BPS Networking Event in Lisbon, Portugal

IMG_20140918_152946The second BPS-supported Portugal Networking Event, took place last month at the Institute of Molecular Medicine (IMM), Faculdade de Medicina, Universidade de Lisboa. Organized by BPS members Ivo Martins; IMM/FMU, Axel Hollmann; IMM/FMUL, and Filomena Carvalho; IMM/FMUL, this intimate event brought together participants from different career stages to discuss the study of protein-ligand interactions via biophysical techniques with an emphasis on peptide-lipid interactions. Ivo Martin, one of the organizers of the event, gives us a quick recap below:

The main objective of the event was to make people aware of the possibilities given by studying protein-ligand interactions via biophysics techniques. The event was a great opportunity to share our work and research on the topic as well as meet and get to know other individuals interested in this scientific field.

Broken up into three parts, the event feature a theoretical, practical, and networking session. The theoretical session gave attendees the chance to present their current research and become familiar with other people’s work on protein-ligand interactions. The practical session gave participants a chance learn practical, hands-on knowledge on how to address the problems and issues typically during measurements. Lastly, the networking session helped foster new relationships and professional connections.

I believe that meetings like this must be held more often, otherwise people, often close by, do not know each other missing great collaborative research opportunities. We certainly will organize similar events in the future.

Were you at the Portugal Networking Event? Share your experience in the comments below!

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Atomic Force Microscopy Data Show Molecular Variations along Collagen I Fibrils

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The cover image is a three dimensional representation of the topography of a hydrated collagen I fibril displaying a localized bend in the otherwise linear structure of the fibril. The color scheme of the image represents the modulus of the fibril with a spatial resolution of 8 nm. The image was generated from data acquired with Peak Force Quantitative Nanomechanical Mapping, an atomic force microscopy mode developed by Bruker. The result of this methodology is a 256 by 256 grid of force curves acquired over a 2 µm x 2 µm region, at indentation speeds of roughly 1 mm/s. This represents an example of recent advancements in mechanical mapping at the nanometer scale in a hydrated environment, and is an essential component for understanding the mechanical properties of biological structures.

The main drive of our research is to understand variations in molecular organization along collagen I fibrils, which are responsible for the mechanical properties of connective tissues such as tendon, ligament, bone, and skin. This image highlights both the localized (fibril bend) and periodic (D-band) fluctuations in molecular interaction and density along the length of a single fibril as depicted in the coloring of the fibril. Our research focus is to study variations in molecular interaction along mechanically damaged collagen fibrils displaying localized alterations. This work will provide insight in to the nanoscale protein response to mechanical damage resulting in the failure of connective tissues.

Further information on our research can be found on our group webpage at:

http://fizz.phys.dal.ca/~kreplak/

- Samuel Baldwin, Andrew Quigley, Charlotte Clegg and Laurent Kreplak

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Elastic Network Used to Simulate the Mechanics of Articular Cartilage

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1) How did you compose this image?

The basic network structure was randomly generated using MATLAB code that was utilized in our research, and then exported into Photoshop to add the details, highlights, and colors.

2) What prompted you to submit your image as cover art?

Lead author Dr. Jesse Silverberg actually has a background in graphic design. In fact, in his life before physics, he spent a year in college studying 2/3D design, color theory, and basic drawing. After realizing the difference between art-for-the-sake-of-art, and art-for-the-sake-of-selling-a-product, Jesse left school and took some time off before reapplying for a physics program at another university. In 10 years of undergraduate and graduate studies, he’s taken every opportunity to exercise his artistic inclinations, including submitting images as journal cover art.

3) How does this image reflect your scientific research?

The image of a randomly generated elastic fiber network was produced using a simulation that was an integral part of our research on articular cartilage, a biological tissue that enables smooth joint motion in mammals. On one hand, it helped us better understand experimental measurements, while on the other, it helped distill a very complex biological tissue into its essential physical components.

4) Can you please provide a few real-world examples of your research?

Roughly 1/3 of adults will get osteoarthritis in their lifetime. This debilitating disease causes joint pain and has few therapeutic options. One promising opportunity lies in the field of tissue engineering, wherein artificially grown tissue transplants are used to replace damaged and degraded cartilage. However, there have been significant challenges in making plausible candidates for transplant surgeries because the mechanical properties of these artificial constructs are inferior when compared to the natural material. Our work provides insights on the microscopic origins of cartilage’s mechanical properties and offers guidance on what steps could be taken for tissue engineers as they work towards viable therapeutic alternatives.

5) How does your research apply to those who are not working in your specific field?

In addition to tissue engineering applications, our work also offers the first example of how the theory of rigidity percolation can be used to describe natural biological tissues. This is exciting because it provides a new lens to view these complex and often hierarchical materials with a relatively well-understood microscopic model.

6) Do you have a website where our readers can view your recent research?

https://cohengroup.lassp.cornell.edu/research.php?project=10020

- Jesse L. Silverberg, Aliyah R. Barrett, Moumita Das,  Poul B. Petersen, Lawrence J. Bonassar, and Itai Cohen

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Be the First BPS Congressional Fellow!

congressional_headerAre you interested in science policy? Intrigued by the ways of Washington?  Wondering how you can use your scientific expertise in ways other than in the lab?  Make sure you consider applying for the Biophysical Society’s Congressional Fellowship.  Applications are due October 14!

The Society is very excited to be sponsoring its first Fellow for the 2015-2016 year. The individual selected as the Fellow will work on Capitol Hill for one year in an office of his/her choosing and participate in the AAAS Congressional Fellowship Program, which has been around for over 40 years and has placed more than 1000 Fellows in Congress.

The Society’s leadership is very enthusiastic about getting involved in the AAAS program since it is more important than ever that policy makers have access to scientific and technical analysis on proposed legislation, and that scientists understand the legislative process.  While BPS members have participated in the AAAS program before, this is the first time members have the opportunity to apply through the Biophysical Society.

The fellowship is open to current BPS members who have been members since at least 2012, are US citizens and hold or will obtain a PhD by January 1, 2015.  This includes early career, regular, and emeritus members!  The fellowship can be done during a sabbatical year, or before or after a postdoctoral position.  Some past AAAS Fellows have used the opportunity to launch a new career path in science policy, while others have used it to improve their understanding of Capitol Hill, and then returned to the bench or industry positions.

For all the details and to access the application, visit the Society’s webpage.  Be sure to get started as soon as possible—there are only a few weeks left to apply.

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Digging Deep in the Membrane

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The ion-transporting activities of many membrane proteins, such as the Na+,K+-pump (or Na+,K+-ATPase), and Na+- and K+-channels, are sensitive to the transmembrane electrical potential difference. In experimental electrophysiological studies, this can be relatively easily controlled via electrodes in the aqueous solutions on each side of the membrane. However, all transported ions must bind to sites of the protein embedded within the membrane and, therefore, the crucial parameter for any rate or equilibrium constant of an ion transport protein’s mechanism is in fact the local electric field strength within the membrane. This is extremely difficult to measure experimentally. The image on the September 16 issue of the Biophysical Journal shows theoretical calculations of the contribution to the electric field strength from K+ ions (above) and Na+ ions (below) bound to the Na+,K+-ATPase. The calculations are based on recently published x-ray crystallographic structures of the protein in K+- and Na+-bound states.

The calculations show that as one moves away from the ion binding sites the field strength decays rapidly through the protein matrix and its surrounding membrane, such that the field strength originating from the bound ions is negligible at the membrane/aqueous interface adjacent to the protein. However, voltage-sensitive fluorescent membrane probes, such as RH421, situated in the membrane adjacent to the Na+,K+-ATPase, respond with large fluorescence changes on addition of Na+ or K+ ions to the protein and have often been used to resolve the kinetics of the enzyme’s partial reactions. What is it then that RH421 is responding to? By studying the interaction of the Na+,K+-ATPase with the large cation benzyltriethylammonium (BTEA), which is capable of binding to the protein’s ion transport sites but, in contrast to Na+ and K+, can’t be occluded within the protein interior, we isolated the conformational change of the protein necessary ion occlusion, rather than ion binding per se, as the origin of the RH421 response. Because RH421 is known to be sensitive to membrane dipole potential, if our model of field strength emanating from ions bound to the Na+,K+-ATPase is correct, a likely explanation for the probe’s response is that the protein conformational change disturbs the lipid packing around the protein. This would lead to a local electric field strength change at the membrane/protein/aqueous solution interface.

The activity of the Na+,K+-ATPase is known to be particularly sensitive to the lipid composition of the membrane. If occlusion reactions perturb the surrounding membrane, as our results indicate, it seems logical that the flexibility and polarisability of the membrane should influence the protein’s activity. Ion occlusion reactions of ion pumps, such as the Na+,K+-ATPase, can be seen as analogous to gating reactions of ion channels. Factors such as the membrane dipole potential, lipid packing and membrane hydrophobic thickness could, therefore, also be important determinants of channel activity and its voltage dependence.

For more information please visit our websites:

http://sydney.edu.au/medicine/people/academics/profiles/helge.rasmussen.php

http://pure.au.dk/portal/en/persons/flemming-cornelius%28311a855e-7d31-46ec-82c8-70be1c3e7b52%29.html

http://pure.au.dk/portal/en/persons/yasser-ahmed-mahmmoud%286025ee23-3dd4-4903-a857-3e68ea282dfd%29.html

http://njms.rutgers.edu/departments/pharmacology/faculty/berlin/research_interests.cfm

http://www.rmit.edu.au/browse;ID=m3cqbgzxl8pr1

and http://sydney.edu.au/science/people/ronald.clarke.php

- Laura Mares, Alvaro Garcia, Helge Rasmussen, Flemming Cornelius, Yasser Mahmmoud, Joshua Berlin, Bogdan Lev, Toby Allen & Ronald Clarke

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The Function of Lung Surfactant and the Lateral Organization of Lipids in Biological Membranes

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The cover image of the September 2 issue of Biophysical Journal shows a lipid monolayer in equilibrium with bilayer vesicles. Both bilayers and monolayers are separated into liquid-ordered and liquid-disordered phases. The bilayers were formed in water (not shown in the image) as a result of monolayer collapse below the equilibrium surface tension. This structure was obtained from molecular dynamics (MD) simulations with the Gromacs software package and the coarse-grained Martini model.

The image was generated from the three-dimensional particle densities using the visualization software Paraview [D. Rozmanov et al., Faraday Discuss., in press]. The densities were sampled on a high-resolution grid (0.2 nm) using a short MD trajectory (1 ns) at the monolayer–bilayer equilibrium. The simulation time to achieve the equilibrium was 25 µs. The monolayer lateral size is 50×50 nm2. The image shows part of the system, corresponding to a patch of ca. 30×22 nm2.

This image is an example of the scale and complexity of systems accessible by the state-of-the-art computer simulations. The coexistence of liquid-ordered and liquid-disordered phases as well as liquid-expanded and liquid-condensed phases was reproduced in a monolayer at an air-water interface, and large-scale collective lipid transformations upon monolayer collapse from the interface were simulated. This work was inspired by questions related to the function of lung surfactant and the lateral organization of lipids in biological membranes. More details on our research can be found on the group webpage at http://www.ucalgary.ca/tieleman/.

- Svetlana Baoukina, Dmitri Rozmanov, Eduardo Mendez-Villuendas, Peter Tieleman

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Everything You Need to Know about BPS Travel Awards for the 2015 Annual Meeting

Only a month remains before the abstract and travel award deadlines for the Biophysical Society’s 59th Annual Meeting, being held February 7-11, 2015 in Baltimore, Maryland. If you are a student, postdoc, early or mid-career scientist looking for a little extra funding to attend the Annual Meeting, be sure to apply for a BPS Travel Award. Check out the FAQ below to learn more about the application process.

What is the Travel Award application deadline?

October 3. Remember: You MUST submit an abstract by October 1 in order to be eligible for a Travel Award.

Can I submit any part of my application late?

No. ALL parts of your application are due by the October 3 deadline – including your letters of recommendation! Start asking your advisers for references now, and be sure to read each award’s description so you know exactly what is required.

I think I’m qualified for both the CPOW and Education Travel Awards. Can I apply for both?

Yes, you can apply for multiple travel awards, as many as you are eligible for. However, you can only be selected to WIN one award.

 Oops! I forgot to submit my abstract by October 1. But I am going to submit a late abstract! Can I still apply for a Travel Award?

No. Only abstracts submitted by the regular deadline (October 1) will be eligible for a Travel Award.

I am a co-author on an abstract, but not a presenting author. Can I apply for a Travel Award?

In most cases, no. For all Education, MAC, and International awards, you MUST be a presenting author on the abstract. If you are not a presenting author, your abstract will be marked as ineligible. This also applies to CPOW awards for postdocs. The only exception is the mid-career CPOW award, for which you must be a co-author or presenting author on a submitted abstract.

When will I find out if I won?

You will be notified on the outcome of your application via email by November 21. Be sure to check your spam folder if you don’t see the email.

My adviser would rather send the letter of recommendation directly to you. Where exactly should he/she send it?

Letters of recommendation can be emailed to Laura Phelan, lphelan@biophysics.org. If your adviser prefers ‘snail mail,’ please have them send it to the attention of Laura Phelan at the Society Office. We are located at 11400 Rockville Pike Suite 800, Rockville, MD 20852. Whether emailed or mailed, all letters must be received (not postmarked!) by the October 3 deadline.

 I am not a US citizen, but I am still a minority researching in the US. Why can’t I apply for the MAC Travel Award?

Because the MAC Travel Awards are funded by an NIH grant, only US citizens or permanent US residents are eligible. Please be sure to check out the Education or CPOW awards to see if you qualify.

I am applying for an Education Travel Award as a postdoc. Why is the application asking me to answer all the questions for undergrads and grad students?

Postdoc Education Travel Awards only require a CV and a copy of your abstract. Please fill out all of the extra questions with ‘n/a’. When the site asks you to upload a copy of a faculty recommendation letter, simply upload a copy of your CV instead. Let us know if you have questions.

I’m international but I live/research/study in the US. Aren’t I still eligible for an International Travel Award?

No, you are not eligible. You must be living and conducting research OUTSIDE of the US in order to qualify for an International Travel Award. If you live/work/study in the US, no matter your origins, you are not eligible for this award.

 But I’m an international postdoc living/researching in the US. Does this mean there are no Travel Awards available to me?

All postdocs are eligible for the Education Travel Award. If you are a female postdoc, you may also be eligible for the CPOW Travel Award. Be sure to review eligibility requirements online.

I am currently a graduate student. However, by the time of the Annual Meeting I will be a postdoc. What award should I apply for?

You should apply for the awards that fits your career level as of October 3. In your case, you must apply as a graduate student.

I am no longer a student or a postdoc. Am I eligible for a Travel Award?

MAC, CPOW, and the International Relations Committee all offer travel awards for junior, senior, and/or mid-career scientists. Please check eligibility requirements online to see if you qualify for any of these awards.

Still confused? Please contact the Society Office at (240)-290-5600 or lphelan@biophysics.org.

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