Researchers use honeybee venom toxin to develop a new tool for studying hypertension
September 17, 2008Researchers at the University of Pennsylvania School of Medicine have modified a honeybee venom toxin so that it can be used as a tool to study the inner workings of ion channels that control heart rate and the recycling of salt in kidneys. In general, ion channels selectively allow the passage of small ions such as sodium, potassium, or calcium into and out of the cell.
The study, published in the Proceedings of the National Academy of Sciences, is from the laboratory of Zhe Lu, M.D, Ph.D., Professor of Physiology and a Howard Hughes Medical Institute Investigator, who looked at the action of a natural bee toxin on inward-rectifier potassium channels, Kir channels for short, to identify new approaches to treat cardiovascular disease.
The honeybee venom toxin, called tertiapin, or TPN, stops the flow of potassium ions across cell membranes by plugging up the opening of Kir channels on the outside of cells. Kir channels in kidneys are potential new targets for treating hypertension. "The clue comes from patients with genetic defects in these channels who lose a lot of sodium because it cannot be effectively reabsorbed and thus have low blood pressure," notes Lu. "An inhibitor specifically against these kidney channels will allow this idea to be tested."
Developing a specific inhibitor for one type of Kir channel has been challenging because the target site is very similar among different types of Kir channels. For example, while TPN inhibits Kir type 1 channels in kidney cells, it also inhibits other types of Kir channels in heart cells. After more than a decade, Lu and his colleagues succeeded in bioengineering a TPN that selectively inhibits Kir channels important for salt recycling in kidneys.
By introducing two mutations into TPN, they engineered a variant, called TPNLQ, which stems the flow of potassium ions in renal Kir type 1 channels at low concentrations, and with a 250-fold sensitivity over six other types of Kir channels.
The development of TPNLQ demonstrates that a highly specific inhibitor of potassium channels can be engineered. TPNLQ can now be used as a tool to prove the concept, in animal studies, that reducing salt reabsorption by plugging up renal Kir type 1 potassium channels is a potential new way to treat hypertension.
Source: University of Pennsylvania
-
Periodic paralysis study reveals gene causing disorder
Jan 07, 2010 |
not rated yet |
0
-
Site used by sodium to control sensitivity of certain potassium ion channels
Sep 18, 2008 |
4.5 / 5 (4) |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
-
Is Everyday Technology Killing Us?
Feb 08, 2012
-
Exercise and weight loss
Feb 08, 2012
-
Why do we have head aches? Our brains can't feel anything.
Feb 07, 2012
-
"The end of diseases" by David Agus, interview from Daily Show with Jon Stewart
Feb 04, 2012
-
Oncolytic adenovirus
Feb 04, 2012
-
Nutrition label stuffs and diets
Feb 02, 2012
- More from Physics Forums - Medical Sciences
More news stories
Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV
A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...
13 hours ago |
5 / 5 (3) |
0
|
Overeating may double risk of memory loss
New research suggests that consuming between 2,100 and 6,000 calories per day may double the risk of memory loss, or mild cognitive impairment (MCI), among people age 70 and older. The study was released today and will be ...
Medicine & Health / Neuroscience
9 hours ago |
5 / 5 (2) |
0
|
Declining health-care productivity in England: Who says so?
Reports that the National Health Service in England has been declining in productivity in the last decade appear to have been accepted as fact. However, a Viewpoint published Online First by The Lancet disputes this. The Vi ...
7 hours ago |
1 / 5 (1) |
1
Injured boomers beware: Know when to see doctor
(AP) -- It happened to nurse Jane Byron years after an in-line skating fall, business owner Haralee Weintraub while doing "men's" push-ups, and avid cyclist Gene Wilberg while lifting a heavy box.
14 hours ago |
5 / 5 (1) |
0
FDA-approved drug rapidly clears amyloid from the brain, reverses Alzheimer's symptoms in mice
Neuroscientists at Case Western Reserve University School of Medicine have made a dramatic breakthrough in their efforts to find a cure for Alzheimer's disease. The researchers' findings, published in the journal Science, show t ...
Medicine & Health / Neuroscience
Feb 09, 2012 |
4.9 / 5 (58) |
17
|
Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy
For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...
New method to examine batteries -- MRI from the inside
There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
Google might launch Drive for cloud storage soon
(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...
Lab study raises questions over nano-particle impact
Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.
Researchers find extensive RNA editing in human transcriptome
In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...