How do protein binding sites stay dry in water?
2011-10-22
(Press-News.org) In a report to be published soon in EPJE¹, researchers from the National University of the South in Bahía Blanca, Argentina studied the condition for model cavity and tunnel structures resembling the binding sites of proteins to stay dry without losing their ability to react, a prerequisite for proteins to establish stable interactions with other proteins in water.
E.P. Schulz and colleagues used models of nanometric-scale hydrophobic cavities and tunnels to understand the influence of geometry on the ability of those structures to stay dry in solution.
The authors studied the filling tendency of cavities and tunnels carved in a system referred to as an alkane-like monolayer, chosen for its hydrophobic properties, to ensure that no factors other than geometrical constraints determine their ability to stay dry.
They determined that the minimum size of hydrophobic cavities and tunnels that can be filled with water is on the order of a nanometer. Below that scale, these structures stay dry because they provide a geometric shield; if a water molecule were to penetrate the cavity it would pay the excessive energy cost of giving up its hydrogen bonds. By comparison, water fills carbon nanotubes that are twice as small (but slightly less hydrophobic) than the alkane monolayer, making them less prone to stay dry.
The authors also showed that the filling of nanometric cavities and tunnels with water is a dynamic process that goes from dry to wet over time. They believe that water molecules inside the cavities or tunnels are arranged in a network of strong cooperative hydrogen bonds. Their disruption by means of thermal fluctuations results in the temporary drying of the holes until new bonds are re-established.
One of the many potential applications is in biophysics, to study water-exclusion sites of proteins, and understand the physical phenomenon linked to the geometry of those sites, underpinning the widespread biological process of protein-protein associations.
INFORMATION: Reference
Schulz EP et al. (2011) Behavior of water in contact with model hydrophobic cavities, tunnels and carbon nanotubes. European Physical Journal E. 34: 114, DOI 10.1140/epje/i2011-11114-8
The full-text article is available to journalists on request.
For more information, see www.epj.org
END
ELSE PRESS RELEASES FROM THIS DATE:
2011-10-22
The University of Pittsburgh Medical Center (UPMC) is known as a leading American health care provider. Yet, despite UPMC's high ranking in hospital rating publications, serious medical errors can and do occur in its facilities.
In early 2011, Michael Yocabet received a kidney from longtime girlfriend Christina Mecannic in an operation performed at UPMC Presbyterian. Although the surgery was completed without incident, it was later discovered that the donated kidney was infected with hepatitis C, which was passed to Yocabet. As a result, UPMC's living kidney donor transplant ...
2011-10-22
Athens, Ga. – A commonly prescribed blood pressure-lowering medication appears to kick start recovery in the unaffected brain hemisphere after a stroke by boosting blood vessel growth, a new University of Georgia study has found.
The discovery, based on a study using rats and published recently in the online journal PLoS ONE, occurred only because the team, led by Susan Fagan, professor of clinical and administrative pharmacy at the UGA College of Pharmacy, struck a new path in stroke research by examining the healthy side of brain after the stroke occurred.
"I'm ...
2011-10-22
Reconstructive surgical approaches can help delay endoprosthetic joint replacement in patients with osteoarthritis. Henning Madry and coauthors introduce such procedures in the current issue of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2011; 108[40]: 669-77).
Articular cartilage defects often develop subsequent to injury or osteoarthritis. The authors in their article provide an overview of currently available medical and surgical therapeutic options. Medical therapy aims to preserve articular function for as long as possible and to delay surgical intervention. ...
2011-10-22
WORCESTER, Mass. — A team of researchers at the University of Massachusetts Medical School, Harvard Medical School, Stanford University and the Prince Felipe Research Centre in Spain have deciphered the complete three-dimensional structure of the bacterium Caulobacter crescentus's chromosome. Analysis of the resulting structure —published this week in Molecular Cell — has revealed new insights into the function of genetic sequences responsible for the shape and structure of this genome.
Scientists know that the three-dimensional shape of a cell's chromosome plays a role ...
2011-10-22
New research reveals how we make decisions. Birds choosing between berry bushes and investors trading stocks are faced with the same fundamental challenge - making optimal choices in an environment featuring varying costs and benefits. A neuroeconomics study from the Montreal Neurological Institute and Hospital – The Neuro, McGill University, shows that the brain employs two separate regions and two distinct processes in valuing 'stimuli' i.e. 'goods' (for example, berry bushes), as opposed to valuing the 'actions,' needed to obtain the desired option (for example flight ...
2011-10-22
A motorcyclist was killed on Interstate 88 in Warrenville, Illinois, on his way to Chicago, when he was thrown from his bike and hit by a passing truck. At the time, Nicholas Linton was riding with a group of other cyclists on his way to Chicago when he lost control, swerved, and was thrown from his bike. The accident is still under investigation; eye witness statements give conflicting reasons for the cyclist's loss of control.
On I-80, another motorcycle rider was thrown from his bike after hitting a bump in the road produced by recent road construction. The rider ...
2011-10-22
"Picture yourself hiking through the woods or walking across a lawn," says Elizabeth Haswell, PhD, assistant professor of biology in Arts & Sciences at Washington University in St. Louis. "Now ask yourself: Do the bushes know that someone is brushing past them? Does the grass know that it is being crushed underfoot? Of course, plants don't think thoughts, but they do respond to being touched in a number of ways."
"It's clear," Haswell says, "that plants can respond to physical stimuli, such as gravity or touch. Roots grow down, a 'sensitive plant' folds its leaves, and ...
2011-10-22
Sexual harassment in the workplace has long been illegal. Title VII of the Civil Rights Act of1964 classifies sexual harassment as discrimination. The specific definition is "unwelcome verbal, visual, or physical conduct of a sexual nature that is severe or pervasive and affects working conditions or creates a hostile work environment."
The EEOC, the federal agency responsible for policing discrimination in the workplace notes the following: Sexual harassment can occur in a variety of circumstances, including but not limited to the following:
- The victim ...
2011-10-22
The court uses a complex set of factors when determining a New Jersey child support award. Child support, intended to provide for the care, maintenance and education of a child, can be a hotly contested issue. In some cases, parents try to manipulate the system in an effort to receive more or pay less. While it is important to make sure that the court has all the facts when considering child support, it is also important to remember why child support exists in the first place -- to support minor children after divorce or when parents never married.
The court evaluates ...
2011-10-22
Consumers who tell little white lies to avoid confrontation might find themselves rewarding the people who inconvenienced them, according to a new study in the Journal of Consumer Research.
"Most consumers have told an inquiring server that their cold meal is fine, a hairdresser that they like their unexpected 'new look,' or a friend that his/her too-snug jeans look great," write authors Jennifer J. Argo (University of Alberta) and Baba Shiv (Stanford University). But according to the researchers, white lies have negative repercussions for the people who tell them.
In ...
LAST 30 PRESS RELEASES:
[Press-News.org] How do protein binding sites stay dry in water?
