Alexander Kobulnicky

Endorphin (leu-enkephalin)
Acrylic on canvas
24” x 36”
2010
$850

The cacophonously-named leu-enkephalin is the simplest of the endorphins, a class of neurotransmitters that mimic the effects of opiates. It was long theorized that opiates imitated the effect of compounds found in the brain, accounting for their unmatched ability to soothe pain. These hypothetical compounds were called “endorphins,” short for “endogenous morphine,” and among the first to be discovered were the enkephalins, in 1975.

Enkephalins are pentapeptides, formed from 5 amino acids joined with peptide bonds. Leu-enkephalin comprises tyrosine, glycine, glycine, phenylalanine, and leucine, while met-enkephalin substitutes methionine for leucine. These differences are fairly trivial, since both enkephalins perform similar functions, and indeed are coded for by the same gene.

In contrast to other endorphins, the enkephalins act mainly on the delta-opioid receptor, which has the strongest analgesic powers, and they have a lesser affinity for the mu-opioid receptors. Enkephalins are thought to be the closest neural analog to morphine, with the tyrosine side-chain bearing a particular resemblance to the shape of the morphine molecule.

These molecules are rendered as space-filling models, in a natural, low-energy conformation, and displayed from an angle that shows off as much of their structure as possible. The atoms are color-coded, with carbon being black, hydrogen white, oxygen red, and nitrogen blue. They are painted in artist-quality acrylics, on gessoed canvas