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Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. Inhibitor binding is either reversible or irreversible. Irreversible inhibitors usually react with the enzyme and change it chemically. These inhibitors modify key amino acid residues needed for enzymatic activity. In contrast, reversible inhibitors bind non-covalently and different types of inhibition are produced depending on whether these inhibitors bind the enzyme, the enzyme-substrate complex, or both. Their discovery and improvement is an active area of research in biochemistry and pharmacology. A medicinal enzyme inhibitor is often judged by its specificity (its lack of binding to other proteins) and its potency (its dissociation constant, which indicates the concentration needed to inhibit the enzyme). A high specificity and potency ensure that a drug will have few side effects and thus low toxicity. Enzyme inhibitors also occur naturally and are involved in the regulation of metabolism. (more...)

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Did you know...

From Wikipedia's newest articles:

...that the Certosa di Pavia (pictured) was commissioned by Gian Galeazzo Visconti to be built halfway between his two courts in Milan and Pavia?
...that Jason Bedrick, a New Hampshire state representative, is that state's first Orthodox Jewish elected official?
...that Chiri Yukie prepared the first Japanese translations of several traditional Ainu yukar as a teenager?
...that the Vedic Mathematics genre was revived after Hindu Shankaracharya Jagadguru Swami Sri Bharati Krishna Tirthaji Maharaja rediscovered it in the form of sixteen sutras?
...that the Department of State Lands is one of Oregon's oldest government agencies?
...that on October 5, 1914, a French Voisin III pilot scored the first air-to-air kill of World War I?
...that Broadway actress Evelyn Hoey was found shot dead in the bedroom of Henry H. Rogers's grandson in 1935?
...that Julien Wiener is the only Jewish Australian Test cricketer?
...that in Boyd, Oregon only the wheat fields are still operational ?
...that Operation Show Me How was a major Interpol drug bust concerning the transporting of heroin within the covers of the children's book Show-Me-How-I-Can-Paint?
...that Peter Gadsden, the 652nd Lord Mayor of London, was born in Canada and became a Companion of the Order of Australia?

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In the news

The Chinese River Dolphin (illustrated) is declared functionally extinct, the first extinction of a large mammal in recent decades.
Suffolk police launch an investigation on five dead bodies discovered near Ipswich in Suffolk, England.
Astronauts on mission STS-116 attempt to retract a solar array on the International Space Station's Integrated Truss Structure.
Former President of Ethiopia Mengistu Haile Mariam is convicted in absentia of genocide by an Ethiopian court for his part in the so-called "Red Terror".
A conference aiming to "review the Holocaust" is held in Tehran, Iran.
In his final speech in office, UN Secretary-General Kofi Annan encourages the United States to provide global leadership whilst respecting multilateralism.
A military funeral is held for former Chilean head of state Augusto Pinochet.

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On this day...

December 15: Hanukkah begins at sunset (Judaism, 2006); Zamenhof Day

1791 - The first ten amendments to the United States Constitution (pictured), collectively known as the United States Bill of Rights, were ratified.
1891 - James Naismith introduced the first version of basketball, with thirteen rules and nine players on each team.
1961 - Former Nazi leader Adolf Eichmann was sentenced to death after being found guilty on fifteen criminal charges, including war crimes and crimes against humanity.
1994 - The web browser Netscape Navigator 1.0 was first released.
1995 - The European Court of Justice handed down the Bosman ruling, allowing footballers in the European Union to freely transfer from one UEFA Federation to another at the end of their contracts.

Recent days: December 14 – December 13 – December 12

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Today's featured picture

Petrified wood, such as this sample found in Petrified Forest National Park, Arizona, United States, is a fossil wood where all the organic materials have been replaced with minerals, while retaining the original structure of the wood. The petrifaction process occurs underground, when wood becomes buried under sediment. Mineral-rich water flowing through the sediment deposits minerals in the plant's cells and as the lignin and cellulose decay, a stone cast forms in its place.

Photo credit: Daniel Schwen
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