Energy-saving chaperon Hsp90

Large conformational changes without ATP consummation

2012-01-16

(Press-News.org) ATP is the major energy source for most organisms and ATPases are the machines, which utilize this fuel, for example to move muscles or cargo in our body. The very abundant chaperone protein Hsp90 has such an ATPase in each of its two monomers. During the last years experiments had suggested that the movement and conformational changes of ATPase proteins are in general strictly linked to ATP binding and hydrolysis (i.e. fuel consumption).

To probe this theory Thorsten Hugel, Professor at the Technische Universitaet Muenchen (TUM) and member of the Nanosystems Initiative Munich (NIM), and his team designed a special three color single-molecule FRET (Förster resonance energy transfer) assay with alternating laser excitation (ALEX) for simultaneous observation of ATP binding and conformational changes. Unexpectedly the experiments revealed that binding and hydrolysis of ATP is not correlated with the large conformational changes of Hsp90. Hsp90 is instead a highly flexible machinery driven by thermal fluctuations.

"Thermal fluctuations are random changes in the structure of the protein – they can be thought of as collisions with water molecules in the environment, which move rather violently at the temperatures in a living organism," says Thorsten Hugel. "Using these clashes to switch back and forth between different conformations, saves Hsp90 valuable ATP." But then what is the task of ATPase in the Hsp90 chaperone? The scientists suspect that co-chaperones and substrate proteins alter the system so that ATP binding or hydrolysis can take a crucial task.

With the newly developed experimental setup, it is now possible to investigate the very complex system in greater detail to resolve this important question. The Munich biophysicists therewith offer a new perspective on the energy conversion in molecular machines.

INFORMATION:

The work was supported by grants from the DFG (Hu997/9-1, SFB 863) and the Cluster of Excellence Nanosystems Initiative Munich (NIM) and the NanoBio-Technology program of the Elite Network of Bavaria.

Original publication:

Heat shock protein 90's mechano-chemical cycle is dominated by thermal fluctuations
Christoph Ratzke, Felix Berkemeier, and Thorsten Hugel,
PNAS, January 3, 2012 vol. 109, no. 1, 161-166 – Doi: 10.1073/pnas.1107930108

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

2011 Marks Another Year of Strong Support Contract Renewals for Digisonics

2012-01-16

Digisonics, the #1 KLAS rated Cardiology PACS and Structured Reporting vendor for four consecutive years, announced that support contract renewals exceeded 90% once again in 2011. This marks the third consecutive year that support contract renewals have exceeded 90%, a testament to customer confidence in the quality of Digisonics support services. Digisonics' focus on providing best-of-class image management and structured reporting systems combined with commitment to excellence in customer support services has led to consistent recognition by independent research groups ...

Surprising results from smoke inhalation study

2012-01-16

MAYWOOD, Ill. -- A Loyola University Chicago Stritch School of Medicine study includes some unexpected findings about the immune systems of smoke-inhalation patients. Contrary to expectations, patients who died from their injuries had lower inflammatory responses in their lungs than patients who survived. "Perhaps a better understanding of this early pulmonary immune dysfunction will allow for therapies that further improve outcomes in burn care," researchers reported. The study is published in the January/February issue of the Journal of Burn Care & Research. First ...

HIA-LI Hosts Long Island Economic Summit; Confidence, Revenue Get Thumbs Up in 18th Annual Economic Survey and Opinion Poll

2012-01-16

Confidence in the Long Island economy is up compared to the national economy according to the 18th Annual Economic Survey and Opinion Poll conducted by Albrecht, Viggiano, Zureck & Company, P.C. (AVZ) in partnership with Long Island Business News and the Townsend School of Business at Dowling College. Nearly half of the survey respondents indicated that revenue had increased. A panel of Long Island business leaders will discuss the survey findings as HIA-LI, the recognized voice for business on Long Island, hosts the Long Island Economic Summit, Thursday, January 26, ...

The concept of 'overactive bladder' serves better commercial rather than patient interests

2012-01-16

"The overactive bladder syndrome has become an accepted way to simplify a complex array of symptoms and leads people to believe that an overactive bladder is an independent disease in itself. However, the truth is not as simple as this, as there are usually several factors at work explaining the symptoms. This is also one of the reasons why so called overactive bladder medications often do not bring the hoped result," says Kari Tikkinen, MD, PhD, from the HUCS Department of Urology. The article on overactive bladder syndrome, which was co-written by Tikkinen, who currently ...

I recognize you! But how did I do it?

2012-01-16

Are you someone who easily recognises everyone you've ever met? Or maybe you struggle, even with familiar faces? It is already known that we are better at recognising faces from our own race but researchers have only recently questioned how we assimilate the information we use to recognise people. New research by the University of Nottingham Malaysia Campus has shown that when it comes to recognising people the Malaysian Chinese have adapted their facial recognition techniques to cope with living in a multicultural environment. The study 'You Look Familiar: How Malaysian ...

Wearing contact lenses can affect glaucoma measurements

2012-01-16

MAYWOOD, Ill. -- A study about how wearing contact lenses affects glaucoma measurements has been named the top presentation at Loyola University Chicago Stritch School of Medicine's annual St. Albert's Day research symposium. First author of the study is Marie Brenner, a fourth-year student at Stritch School of Medicine. Brenner and colleagues studied the effects of contact lens wear on retinal nerve fiber layer measurements, which ophthalmologists use to diagnose and manage glaucoma. The researchers found that in patients with lower refractive errors, better quality ...

AGU journal highlights -- Jan. 13, 2012

2012-01-16

The following highlights summarize research papers that have been recently published in Journal of Geophysical Research-Oceans (JGR-C), Journal of Geophysical Research-Planets (JGR-E), Journal of Geophysical Research- Biogeosciences (JGR-G), and Geophysical Research Letters (GRL). In this release: Variability of North Atlantic heat transport observed from instrument data Methane exceeds nitrous oxide in rivers' contribution to warming Waste recycling primary source of energy in deep ocean Record Arctic ozone depletion could occur again Traveling supraglacial ...

Affiliate Boosters to Give Away GBP1,000 in Cash -- 80% Commission Offered to All Affiliates

2012-01-16

Affiliate Boosters will be giving away GBP1,000 in cold hard cash at the London Affiliate Conference 2012. All affiliates attending the LAC are eligible to win. There will be 2 draws with a GBP500 prize each and to be in for a chance of winning. Affiliates can enter by dropping off a business card at the Affiliate Boosters booth, stand 115 and 116 at some point throughout the 2 days. The two drawings will take place at 15:45 on Friday, 27th of January, and at 16:15 on Saturday, 28th of January at the Affiliate Boosters stand. Head of Affiliate Boosters, Lawrence ...

Keeping an eye on the Universe

2012-01-16

The University of Arizona's Catalina Sky Survey keeps a watchful eye on asteroids that might cross the Earth's path. A byproduct of that effort is the largest database compiling the brightnesses of 200 million objects in the universe, including supernovae and stars torn up by super-massive black holes. The night sky is filled with objects such as asteroids that dash across the sky and others – such as exploding stars and variable stars – that flash, dim, and brighten. Studying such phenomena can help astronomers better understand the evolution of stars, massive black ...

Avis Israel Provides Economical iPad 2 Option for Rental Customers

2012-01-16

Devoted to making sure the Israel car rental experience is a positive one, Avis Israel has recently provided an option to rent an iPad 2 with unlimited Wi-Fi connectivity and included GPS for $16 a day to all rental car customers. Soon to be available throughout Israel, the new service is immediately available at the following central branches: Ben Gurion Airport, Jerusalem and Tel Aviv. The iPad 2 is a tablet computer designed, developed and marketed by Apple. It serves primarily as a platform for audio-visual media including books, periodicals, movies, music, games, ...

Energy-saving chaperon Hsp90

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: