Monday, December 19, 2011

Monday's Molecule #154

Today's molecule is a bit more complicated than some of the others. You have to identify the molecule (common name only) and describe (briefly) its function. Can you name the precursor?

Post your answer in the comments. I'll hold off releasing any comments for 24 hours. The first one with the correct answer wins. I will only post correct answers to avoid embarrassment. This is your last chance to enter the Christmas draw for a free textbook!

There could be two winners. If the first correct answer isn't from an undergraduate student then I'll select a second winner from those undergraduates who post the correct answer. You will need to identify yourself as an undergraduate in order to win. (Put "undergraduate" at the bottom of your comment.) Every undergraduate who posts a correct answer will have their names entered in a Christmas draw. The winner gets a free autographed copy of my book! (One entry per week. If you post a correct answer every week you will have ten chances to win.)

Some past winners are from distant lands so their chances of taking up my offer of a free lunch are slim. (That's why I can afford to do this!)

In order to win you must post your correct name. Anonymous and pseudoanonymous commenters can't win the free lunch.

Winners will have to contact me by email to arrange a lunch date.

UPDATE: The molecule is thyrotropin-releasing hormone. It's derived from a long precursor protein containing multiple repeats of the tripeptide Glu-His-Pro.

The winner is Joseph C. Somody.

I'll announce the undergraduate winner of my textbook on Christmas day.

Nov. 2009: Jason Oakley, Alex Ling
Oct. 17: Bill Chaney, Roger Fan
Oct. 24: DK
Oct. 31: Joseph C. Somody
Nov. 7: Jason Oakley
Nov. 15: Thomas Ferraro, Vipulan Vigneswaran
Nov. 21: Vipulan Vigneswaran (honorary mention to Raul A. Félix de Sousa)
Nov. 28: Philip Rodger
Dec. 5: 凌嘉誠 (Alex Ling)
Dec. 12: Bill Chaney


  1. Thyrotropin-releasing hormone (TRH), also called thyrotropin-releasing factor (TRF), thyroliberin or protirelin

    a tropic tripeptide hormone that stimulates the release of thyroid-stimulating hormone and prolactin by the anterior pituitary.

  2. The molecule is thyrotropin-releasing hormone.

    It's a hormone that stimulates the release of thyrotropin or thyroid-stimulating hormone in the pituitary gland.

    The hormone precursor is synthesized as a polypeptide chain containing multiple copies of the peptide -Glu-His-Pro-Gly-, which is cleaved to form mature TRH.

  3. Molecule # 154 is the Thyrotropin Releasing Hormone (TRH), or pyroglutamyl-histidyl-prolinamide (pGlu-H-Pro-NH2). It binds to a receptor of the anterior pituitary causing it to release TSH (Thyrotropic Stimulating Hormone).

  4. That's thyrotropin-releasing hormone AKA protirelin. That's a good one because it is linked to a Nobel prize in medicine (1977).
    The function is kind of obvious from the name - it stimulates secretion of thyrotropin.

    It is basically a EHP peptide with Glu condensing on itself. So the immediate precursor has to be simply EHP.

  5. Hmm, it appears to be thyrotropin releasing hormone. It is released by the hypothalamus into the hypophyseal portal system. I do not know what the precursor is exactly. Its function is stimulating the release of thyroid stimulating hormone and prolactin from the anterior pituitary.

    If I'm right, it would be due to my intense review for the MCAT.

    Roger Fan

  6. It is TRH, thyrotropin releasing hormone. It is secreted from the hypothalamus and interacts with TRHR in the anterior pituitary, causing the release of TSH, thyroid stimulating hormone.