Receptors stud membranes on their surfaces so that they are accessible for binding.
When receptors become bound, they signal a series of molecular reactions targeting DNA. T
his type of receptor is called a G-protein coupled receptor. Their activation signal is amplified by the coupled second messenger.
Steroid hormones do not act via this second messenger mechanism. Steroids interact directly with DNA.
Nuclear receptors regulate the processes of homeostasis, reproduction and metabolism. Nuclear hormone receptors function as ligans activated transcription factors.
When bound nuclear receptors promote DNA transcription.
These factors link the signalling molecules (hormones) that control these processes to a responses that results in protein synthesis via translation.
These receptors bind with an assortment of hydrophobic ligands. These include the lipid soluble steroid hormones (estrogens, glucocorticoids, mineralcorticoids and androgens).
Other hydrophobic ligands that bind with nuclear receptors include vitamin D, thyroid hormones, fatty acids, leukotrienes and prostaglandins.
Nuclear receptors that have no identified natural ligans are called nuclear orphan receptors. The search for ligands that can bind with orphan receptors is the subject of intense research.
The sequence of nucleic bases or DNA sequences that code for the proteins that make up the binding domain of receptors are all compiled in a database. The use of this data constitutes the science of bioinformatics.
Bioinformatics or computational biology is the study of this information. It is used to help design drugs and novel experiments.
Biological receptors bind to their targets via a lock and key mechanism. This interaction utilizes a sophisticated molecular recognition system based on spatial fitting.
Receptors include cell membrane bound proteins, antibodies, nuclear membrane receptors, enzymes and ribozymes. They are found in muscle cells, nerve cells, eggs and sperm cells, T-cells as well as viruses, and bacteria.
The chemistry and language of receptor biology is very complicated. The Athlete’s Diet eliminates much of the chemistry and stresses the importance of visualizing the receptor as a protein whose purpose is to bind with one specific ligans. The consequence of that binding causes the effect of the ligans.
The structural similarity of steroids and plant saponins, neurotransmitters and alkaloids, alcohol and GABA receptors or opiates and endorphin receptors allows these ligands to produce their effects.
Human life itself is the result of the bonding of a spermatoid with an ovum.
It is the structural similarity of ligands, not their chemistry that permits binding.
Conventional science when I attended school stressed chemistry over structure. This forced students to memorize insignificant details to predict chemical behavior.
Advances in combinatorial chemistry eliminated that need. There are now libraries of molecules that contain, at least with the aid of a combinatorial algorithms and bioinformatics, all possible combinations or universe of isoforms.