A simple molecule it seems
That affects cell membranes
By changing conformation just so
Permitting a messenger to go
About its role in playing fast
Causing amazing effects that last.
For within the intricate structures of the cell
Nothing is more complex than the molecules that dwell
In a jumbled heap they appear,
Until X-rays made it clear
That those twist and turns
Are needed for the effectors.
Such it is that GPCR's are modified
So that events outside
Are able to induce some special action
That is within the cell, sanctioned
To result in a very specific event
That sometimes in cascades are sent.
But what exactly are GPCR's
Is a secret known by some authors
Who forget that everyone must start
At the beginning to learn the art
And unless the meaning is made clear
It's outside looking in, that clouds the beer.
A GPCR is simply put
Nothing more or less, but
An acronym for a named receptor
That's the R, to the professor
Preceded by the C in terms, simple
To which something is coupled.
Which brings us to the P
Which is for a protein, as we shall see.
And the G is for a type of protein
Which dependent on the receptor's mein
Causes a specific action when it's bound
To the receptor site allowed.
This functional site to which a chemical may bind
Is called an orthostatic (primary) ligand site,
Which means that it is so designed
To confirm to some physical characteristic
To effect its role on the cell system
Producing a cascade.
So now we have a GPCR in total
That has wide ranging effects it's told.
For on that receptor site
If a specific protein should alight
Will cause a reaction of minuteous form
Within the cell on which it's worn.
Sounds a bit complex to understand
But that's the beginning of mice and man
As well as plants and other organism
That have a way to communicate in this fashion
As the environment in which cells survive
Effects their activities when alive.
But wait, there's a cloud in our understanding,
For there are compounds that are called allosteric modulators.
Finding a point of attachment away from the orthostatic site
They somehow change the configuration of the membrane
So that a compound targeted for the primary site,
Suddenly has enhanced activity outright to its delight.
It's a bit like when you spread wide your face
So your tongue can take a favored place
Jutting out just so
To produce a comedy show.
The tongue is like a GPCR now prominent
To accept an effector to begin a new event.
Now for all those who take medications
'Drugs' as said in less sophistication,
These GPCR's, G Protein Coupled Receptors,
(For which I prefer G Protein CROSS-MEMBRANE receptor)
Have the task of recognizing if they may act
On provoking some kind of chemical pact.
Take for example drugs that are given
To aid someone schizophrenia driven,
It is important to know
There are three actions to show:
Positive, Negative and Cognitive by name
Whose actions are not the same.
Positive GPCR's are directed at paranoia
And hallucination actions that destroy.
Negative GPCR's hopefully prevent
The loss of speech in the schizophrenia event.
While Cognitive GPCR's are directed at those involving
Loss of memory and attention subsisting.
Sad to say while this is known,
Most drugs don't act alone
And while the intent of the Medical Profession is clear
An arsenal of Drugs is plainly not here.
So they do the best that can be expected
And a drug may cause harm is often suspected.
While it is possible that a well chosen drug may have value,
It's often discovered that its effect is on other GPCReceptors
Having unintended consequences
Far from the targeted events
As example, a drug for Parkinson‘s disease
Can cause plaques to form in heart tissue.
Estimates range from thirty to fifty percent of drugs
Act by the mechanism of GPCRs,
Information not known before this decade of research
That has much to add in the search
For new and better drugs that will
Hopefully, save – and not kill!
And to quote a recent author on this subject,
'Researchers are just beginning to tackle this new frontier.
Exactly how they will harness the emerging knowledge
About allosteric modulation and functional selectivity
To create better drugs remains to be seen. '
What you see, taste, smell and hear
all have their origin in the first dear
Fifteen days of life's twist and turns,
Building an information base in man (and worms)
That in its complexity
Is beyond human understanding.
Living organism, including man
Have developed in an organized plan
That from the beginning
Has been about life and living.