Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemical strategy hints at better drugs for osteoporosis, diabetes

17.06.2014

By swapping replacement parts into the backbone of a synthetic hormone, UW–Madison graduate student Ross Cheloha and his mentor, Sam Gellman, along with collaborators at Harvard Medical School, have built a version of a parathyroid hormone that resists degradation in laboratory mice. As a result, the altered hormone can stay around longer — and at much higher concentration, says Gellman, professor of chemistry at the UW.

Hormones are signaling molecules that are distributed throughout the body, usually in the blood. Hormones elicit responses from only those cells that carry appropriate receptor molecules. "Receptors have evolved to recognize a very specific signal in a sea of biological fluids that is full of molecular messages," Gellman says.

The relationship between a receptor and its signaling molecule is often likened to that between a lock and a key.

"We're excited because we have preserved the ability to activate the receptor" by altering the backbone of the hormone, which holds the essential contact points in place, Gellman says. "While retaining, even enhancing, the signaling ability, we have diminished the peptide's susceptibility to the biodegradation mechanisms that nature uses to eliminate signals over time."

Peptides are segments of proteins. Peptide hormones, like the better-known steroid hormones such as estrogen and testosterone, can convey a signal to billions of cells at once, even at tiny concentrations.

For a study published June 15 in Nature Biotechnology, the researchers altered a highly successful synthetic parathyroid hormone called teriparatide, which is used to combat severe osteoporosis.

But the real excitement of the discovery is the potential impact on a large class of peptide drugs, Gellman says. "A substantial group of receptors, including some involved in diabetes, respond to peptide signals, but peptides are quickly degraded in the body. Our approach seems to suggest a general strategy to retain the ability to target a specific receptor while diminishing the action of degrading enzymes. The key is that the receptor is looking for one shape while the destructive enzyme seeks a different shape."

Gellman says the idea of replacing segments of the peptide backbone with artificial units once seemed heretical. "Most people expected that you could not change the backbone, which alters the spacing and orientation of the essential contact points, without making the molecule unrecognizable to the receptor."

Gellman has assigned his rights for the discovery to the Wisconsin Alumni Research Foundation. The study's first author, Cheloha, is a Ph.D. candidate in chemistry at UW-Madison. Co-author Thomas J. Gardella led a team at Harvard Medical School that conducted the biological assessments.

Potentially, the "alter-the-backbone" strategy could allow oral dosing of the rather fragile peptide drugs, which today must be injected to avoid destruction in the stomach and small intestine. By protecting the drugs from degrading enzymes, the new approach could also help sustain higher drug concentrations in the bloodstream.

The altered backbone also seems to make minor changes in signals that the receptor, once activated, transmits into the cell, Gellman says. "Changing the sites of backbone modification results in different profiles of response. Building drug molecules that activate only a certain type of response might allow us to dial out undesired side effects; but that's just a hope at this point."

To date, much of the focus on drug development has concerned the external features of signaling molecules, which directly contact a receptor, Gellman says. "The traditional approach is to keep the skeleton the same and modify the surface components. Our approach is just the opposite, keep the surface components the same, and modify the skeleton. Now that it is clear that this non-traditional approach can be successful, others are likely to try it."

###

The research was funded by National Institutes of Health grant #GM056414 and other sources.

—David Tenenbaum, 608-265-8549, djtenenb@wisc.edu

Sam Gellman | Eurek Alert!
Further information:
http://www.wisc.edu

Further reports about: concentrations drugs enzymes hormones osteoporosis receptor signals skeleton

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>