The Mystery Molecule Page: 2008

December

The molecule shown in red inhibits the kinase shown in green and, when the kinase is part of a translocation fusion protein, helps to treat leukemia. Are you “abl” to guess what it is? 

Imatinib
The abl gene on chromosome 9 codes for a tyrosine kinase (similar to one found in the “Abelson” leukemia virus). In chronic myelogenous leukemia, a cytogenetic translocation moves the abl gene next to a region on chromosome 22 (called the “breakpoint cluster region” or bcr). The new version of chromosome 22 is called the “Philadelphia chromosome”. The resulting bcr-abl fusion protein is involved in the pathogenesis of the leukemia, and its tyrosine kinase activity is the target of the drug imatinib (tradename: Gleevec).
 


November

 

Scientists Martin Chalfie, Osamu Shimomura and Roger Tsien won the Nobel Prize for Chemistry last month because of their “glowing” work with this small protein. Can you guess what it is? 

November 2008 Molecule of the Month

 

Green Fluorescent Protein
This unusual protein, originally isolated from jellyfish, has amino-terminal and carboxyl-terminal beta-pleated sheet motifs that form a barrel. The alpha-helical middle portion of the protein, which runs through the barrel, is the chromophore. Cells genetically modified to express one of the many different forms of green fluorescent protein remain colored under ultraviolet light and this feature may be used to study them in an enormous variety of ways.


October

 

Television actor Bryan Cranston won an Emmy award last month for his portrayal of a chemistry professor who moonlights making this molecule and selling it illegally. Can you guess what it is?

October 2008 Molecule of the Month 

Methamphetamine
The high school chemistry teacher Cranston plays in the series “Breaking Bad” manufactures and sells methamphetamine (“crystal meth”), a sympathomimetic drug whose psychostimulant properties make it a popular drug of abuse.


  September

This molecule found in grapefruit juice may increase the potency of many medications taken by mouth. Can you guess what it is?

September 2008 Molecule of the Month

 

Furanocoumarin
This molecule is produced by many plants but is especially high in grapefruit juice. It inhibits cytochrome enzymes in the intestine that help metabolize many drugs (jncluding the somewhat similar-appearing anticoagulant warfarin). Many patients are cautioned to avoid taking their medication with grapefruit juice to avoid the increase in blood concentration which will occur, but some physicians think that the chemical, if added to certain medications, can help absorption and boost the drug’s effect.


  August

This molecule will be slathered on a lot of bare skin this month. Can you guess what it is?

August 2008 Molecule of the Month

 

Para-amino-benzoic acid (PABA)
This common sunscreen absorbs ultraviolet light. The US does not have mandatory standards for determining the “sun protection factor” (SPF) and most commercially available sunscreens with PABA do not provide as much protection against the ultraviolet “A” radiation (which causes DNA damage) as they do against ultraviolet “B” radiation (which causes typical sunburn). The FDA is considering regulating these products in the future.

 


  July

This molecule is the reason why many baby bottles have been banned recently. Can you guess what it is?

July 2008 Molecule of the Month

 

Bisphenol-A
This industrial chemical (short hydrocarbon chain with two phenols on either side) helps make polycarbonate plastics more lightweight and heat-resistant. Recent research has revealed that it may leach out after frequent washes. Although there is significant controversy over whether exposure to this chemical has any adverse effects (including impact on learning potential), a billion-dollar class action suit against bottle manufacturers has been filed.


 

June

Lorenzo Odone, who suffered from adrenoleukodystrophy, recently died. The “oil” which his parents used to treat him contained glycerol esters of oleate as well as this unusual fatty acid. Can you guess what it is? 

June 2008 Molecule of the Month

 

Erucic acid
Made famous by the 1992 motion picture “Lorenzo’s Oil”, Mr. Odone died of pneumonia at the end of May at the age of 30. His survival with this X-linked disorder in which very long chain fatty acids accumulate and damage the nervous system (and the adrenal) was due to his parents’ adding a blend of cooking oils to his diet. Although the mechanism is unknown, researchers have recently shown that the mixture is effective.

 


  May

Dr. Steven Levine reviewed California’s program for newborn screening at our March meeting and described this molecule as an “escort” for fatty acids. Can you guess what it is?

May 2008 Molecule of the Month

 

 

Carnitine
Although fatty acids provide energy when they are oxidized in the mitochondria, activated fatty acids in the cytoplasm can not simply diffuse across the mitochondrial membrane. The fatty acid is transferred from coenzyme A to carnitine for transport into the mitochondrion, where it is handed back to another coenzyme A molecule on the other side. Dr. Levine described how the state of California uses tandem MS to screen for disorders of carnitine transport in neonates.


March

The U.S. military just destroyed a satellite in space to prevent this molecule from causing harm if it had been allowed to crash to earth. Can you guess what it is?

March 2008 Molecule of the Month

Hydrazine
This colorless liquid is frequently used as rocket fuel. Although conspiracy theorists (and several foreign governments) may have suspected that there was another reason for our shooting down an aging satellite falling out of orbit last month, the real reason was to prevent release of this highly flammable (and carcinogenic) material when it crashed to earth.


February

In his presentation at our local section meeting last month, AACC president Larry Broussard used famous cases to illustrate principles of toxicology, including the drug that ended this star’s life. Can you guess what it is?

 

 

February 2008 Molecule of the Month 

 

Secobarbital
This barbiturate was the cause of death for Judy Garland in 1969, as well as other famous singers and movie stars such as Jimi Hendrix and Marilyn Monroe, as described by Dr. Broussard in his presentation. Sadly, he can now add others (such as Heath Ledger) to his list in the future. To see photos from the awards dinner, visit the Northern California Section Awards page.


 

January

To try to prevent widespread use of generic versions, the manufacturer of this famous drug is promoting its endorsement by the inventor of the artificial heart. Can you guess what it is?

January 2008 Molecule of the Month

 

 

Atorvastatin (Lipitor)
Statins are inhibitors of the enzyme HMG-CoA reductase, an important step in the production of cholesterol. With many different statins to choose from (and generic versions of the current “brand names” on the way), pharmaceutical companies are trying to keep brand loyalty by having famous cardiologists (such as Dr. Robert Jarvik, inventor of the artificial heart) endorse their versions.

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