Phosphorylation
Methylation 

21    E313       C313

23    E337#    C337#

23    E339#    C339#

23    E341#     C341#

23    E361*      C361*

23    E363*     C363* 

24    E389*     C389*

Serum samples from the same species had Cxxx compounds but not Exxx compounds. We propose that the E compounds were storage forms and that conversion from Exxx compounds to Cxxx compounds is the last step before secretion. The enzyme that catalyses this step iwould be an N-methylase. 

N-methylase is a B12-dependent enzyme. It catalyses the three sequential methylations converting a phosphoethanolamine to a phosphocholine.  The structures on the right show a typical substrate (upper panel) and product (lower panel). We found no evidence for partially methylated intermediates. 

 

N-Methylase is regulated by cortisol. It would be a useful component of the fight or flight response and could also be a key element during childbirth. 

The table on the right lists all of the major phosphoesters we identified in bovine adrenal extracts. The first column shows the number of carbon atoms in each molecule. # identifies the spiral lactones. * identifies the open ring intermediates. The E compounds (phosphoethanolamine esters) were separated from the C compounds (phosphocholine esters) by HPLC. Individual column fractions were anlysed by LC-MS and by RIA for DLM.

Chasalow F. A new concept: Ionotropin may be a factor in mobilization for [a] the flight or fight response and [b] child birth. EC Paediatrics 7.9: 909-918 (2018).

Doi: 10.31080/ecpe.2018.07.00341