Navigation Links
Lead With a Poisonous Electron Shield

It has been speculated that lead poisoning may have played a role in the fall of the Roman Empire: it is thought to have been caused by the concentration of grape juice// in lead containers.

Though the introduction of lead-free gasoline has reduced damage to the environment, the annual production of lead continues to increase worldwide because lead is still used in batteries, glass, and electronic components. However, there has thus far been little research into what, at a molecular level, causes the toxic effects of lead. French researchers have now applied quantum chemistry to very simple enzyme models and gained new insights. As they have reported in Angewandte Chemie, it seems that the lead’s “electron shield” is the main culprit.

Lead does the most damage to the nervous system, kidneys, liver, brain, and blood. These kinds of damage are especially severe for children as they can be irreversible. Complexation agents that grab onto the metal cations are used as antidotes. However, these agents are not lead-specific, meaning that they also remove other important metal cations from the body.

C. Gourlaouen and O. Parisel (Laboratoire de Chimie Théorique, Université Paris 6) took a closer look at two proteins to which lead likes to bind. Calmodulin, a calcium-binding protein, plays an important role in regulating and transporting the calcium cation in the human body. A calcium ion binds to seven ligands at the active centers of the enzyme. If one of the four possible calcium ions of calmodulin is replaced by lead, the lead ion remains roughly heptacoordinated, but this active center becomes distorted and inefficient; the three remaining sites get a reduced efficiency.

d-Aminolevulinic acid dehydratase is essential for the biosynthesis of hemoglobin. Inhibition of this enzyme disrupts the formation of blood to the point of anemia. At the active center, a zinc ion binds to four ligands, three of which involve a sulfur at om. When lead replaces zinc, it only binds to the three sulfur atoms. The reason for this is the emerging free electron pair of the lead cation. It acts as an electronic shield on one side, pushing away the fourth ligand. Such a dramatic geometrical distortion at the active center could explain why lead inhibits this enzyme.

The different behavior of lead in these two enzymes demonstrates that it can enter into complexes in which the metal–ligand bonds can either point in all directions, or into only one hemisphere, while the other hemisphere is filled by the free electron pair. This observation may help in the design of future lead-specific antidotes.

Source-EurekalertSRM
'"/>




Related medicine news :

1. Poisonous Parkinsons molecule discovered
2. Poisonous Gas Caused Mass Extinction
3. Caution: Apricot Seeds May Be Poisonous
4. Hong Kong Citizens Fear over Poisonous Vegetables in Local Markets
5. Investigators Find Poisonous Chemicals In Four More Drugs In China
6. Lakhs of Indians Exposed to High Levels of Poisonous Gases
7. Four of Family Died After Consuming Poisonous Mushrooms
8. Electronic nose by Italian scientists
9. Stem Cells Could Replace Electronic Pacemakers
10. Electronic Skin (E-Skin) To Robots
11. $ 1.7 Million NYSTAR Award for Binghamton University to Flex Electronics Research Muscle.
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/27/2016)... (PRWEB) , ... June 27, ... ... in the patient payment industry today announced its strategic partnership with Connance, ... system workflows. , The two companies’ proven, proprietary technology combine to provide ...
(Date:6/26/2016)... ... June 26, 2016 , ... On June 10-11, 2016, A Forever ... Cereal Festival and World’s Longest Breakfast Table in Battle Creek, MI, where the rehabilitation ... as home to some of the world’s leading providers of cereal and other breakfast ...
(Date:6/26/2016)... , ... June 26, 2016 , ... ... once they have been diagnosed with endometriosis. These women need a treatment plan ... require a comprehensive approach that can help for preservation of fertility and ultimately ...
(Date:6/25/2016)... ... ... "With 30 hand-drawn hand gesture animations, FCPX users can easily customize each ... Film Studios. , ProHand Cartoon’s package transforms over 1,300 hand-drawn pictures into hand ... select a ProHand generator and drag it above media or text in the Final ...
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, Van Mitchell, ... at Work award to iHire in recognition of their exemplary accomplishments in worksite health ... annual Maryland Workplace Health & Wellness Symposium at the BWI Marriott in Linthicum Heights. ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016 Research ... World Market for Companion Diagnostic Tests" report to their ... Market for Companion Diagnostics The World Market ... and personalized medicine diagnostics. Market analysis in the report includes ... Test Market (In Vitro Diagnostic Kits) by Region (N. America, ...
(Date:6/24/2016)... 24, 2016  Arkis BioSciences, a leading innovator ... more durable cerebrospinal fluid treatments, today announced it ... funding is led by Innova Memphis, followed by ... private investors.  Arkis, new financing will accelerate the ... market release of its in-licensed Endexo® technology. ...
(Date:6/23/2016)... 2016 Research and Markets has ... by Type (Organic Chemical (Sugar, Petrochemical, Glycerin), Inorganic Chemical), ... Parenteral) - Global Forecast to 2021" report to ... The global pharmaceutical excipients market is projected to reach ... 6.1% in the forecast period 2016 to 2021. ...
Breaking Medicine Technology: