28-03-2015, 03:45 AM
(27-03-2015, 12:28 PM)-Clelia- Wrote: hey Lotus, dont worry, all the biochemical information is also good. Now you know how many mechanisms are involved in signal pathways I think that enhance signalling of the cells should be ok, and the fluidity of the membrane can help this. We know that a good diet can benefit these pathways for our healthy. This NBE bring you to be healtier, and well informed, and that is a nice thing. See you soon
Clelia,
Believe it or not, I was actually thinking what if ER-beta could be shifted to ER-alpha, you know.....(in layman terms).....how E2-shifts back and forth to E3 and back again (or, heterodimerize for the scientific). Well, ...wouldn't you I went looking for some research and sure enough......it's called co-synthesis of ER subtypes. But a stronger expression of co-type ER-b down-regulates ER-a expression. Which means (or explains) slow breast growth response from some phytoestrogens that have a preferential binding to ER-beta (e.g, PM, soy, gensitien).
Single-Chain Estrogen Receptors (ERs) Reveal that the ERa/b Heterodimer Emulates Functions of the ERa Dimer in Genomic Estrogen Signaling Pathways
http://www.ncbi.nlm.nih.gov/pmc/articles...9995-04.pdf
The Importance of ERα/ERβ Ratio in Breast Cancer: Mitochondrial Function and Oxidative Stress
http://cdn.intechopen.com/pdfs/23375/InT...stress.pdf
Quote:preferential binding affinity for human ER beta over ER alpha (difference up to 18-fold).
Quantitative structure-activity relationship of various endogenous estrogen metabolites for human estrogen receptor alpha and beta subtypes: Insights into the structural determinants favoring a differential subtype binding.
Abstract
To search for endogenous estrogens that may have preferential binding affinity for human estrogen receptor (ER) alpha or beta subtype and also to gain insights into the structural determinants favoring differential subtype binding, we studied the binding affinities of 74 natural or synthetic estrogens, including more than 50 steroidal analogs of estradiol-17beta (E2) and estrone (E1) for human ER alpha and ER beta. Many of the endogenous estrogen metabolites retained varying degrees of similar binding affinity for ER alpha and ER beta, but some of them retained differential binding affinity for the two subtypes. For instance, several of the D-ring metabolites, such as 16 alpha-hydroxyestradiol (estriol), 16 beta-hydroxyestradiol-17 alpha, and 16-ketoestrone, had distinct preferential binding affinity for human ER beta over ER alpha (difference up to 18-fold). Notably, although E2 has nearly the highest and equal binding affinity for ER alpha and ER beta, E1 and 2-hydroxyestrone (two quantitatively predominant endogenous estrogens in nonpregnant woman) have preferential binding affinity for ER alpha over ER beta, whereas 16 alpha-hydroxyestradiol (estriol) and other D-ring metabolites (quantitatively predominant endogenous estrogens formed during pregnancy) have preferential binding affinity for ER beta over ER alpha. Hence, facile metabolic conversion of parent hormone E2 to various metabolites under different physiological conditions may serve unique functions by providing differential activation of the ER alpha or ER beta signaling system. Lastly, our computational three-dimensional quantitative structure-activity relationship/comparative molecular field analysis of 47 steroidal estrogen analogs for human ER alpha and ER beta yielded useful information on the structural features that determine the preferential activation of the ER alpha and ER beta subtypes, which may aid in the rational design of selective ligands for each human ER subtype.
http://www.ncbi.nlm.nih.gov/pubmed/16728493