PROLINE
In my BIOL 1362 course, we had done amino acids and proteins, further into the course I found about a very interesting amino acid known as Proline. So I scoured the internet and looked up some of my amino acid contacts looking for the infamous Proline. Eventually, I got an exclusive interview with the one and only.
Welcome fellow bloggers, to this exclusive interview soo here’s some background information on amino acids.
There are 20 naturally occurring amino acids.
Amino acids are the building blocks or starting materials if you will of proteins. These residues can either essential or non-essential.
Essential amino acids cannot be synthesised within our bodies we must provide them through our diets. For example Tryptophan is an essential amino acid.
Non-essential amino acids are produced by our bodies. These include arginine, aspartic acid and glutamate.
Besides linking to form di-peptides, oligo-peptides and proteins, they have other functions,
Amino acids are precursors for neurotransmitters likes serotonin, which can be used to transmit messages by the brain and nervous system.
Amino acids can be converted to pyruvate and acetyl CoA and oxidized by the mitochondria. This occurs when worn out or used proteins are broken down into its starting constituents. They are used a s source of energy.
Amino Acid are classified or separated into several groups:
Now as we can see here Proline is non-polar and contains an uncharged R group, LADIES AND GENTLEMEN please help me welcome , PROLINE!!!!!!!!!!!!!!!
[APPLAUSE] [APPLAUSE] [APPLAUSE] [APPLAUSE] [APPLAUSE] [APPLAUSE]
Interviewer: Hi Proline welcome, well as you know as a biochemist I am very interested in getting to know you not just as an amino acid but as the real you. Please share with me and the audience what it’s like to be Proline.
Proline: Well, there is not much to say, you have pretty ,much covered me in the intro. I am a non-polar amino acid with an uncharged R group.
Interviewer: You, are a well known amino acid, my friend I have heard so much about you, like where can you be found, who are you dating, we’re do you hang out?
Proline: Well as you can see my structure I am very unique.
Interviewer: Yes, yes you are, audience did you know that Proline is the only amino acid has its side chain connected to the protein backbone, not once but TWICE! Amazing!
Proline: Thank you I form a five membered ring, which contains nitrogen so technically I am not an amino acid I am an imino acid.
Interviewer: “Gasps” You heard it here, folks unfiltered and uncut! Not an amino acid!!! Because it you contain a NH2+ group not a NH3 group, in this form, correct.
Proline: Yes that’s correct!
Interviewer: Now, let’s talk movies and your roles in movies, you play an important role in the movie called Molecular Recognition.
Proline: Yes, more in depth with intracellular signalling to be exact.
Interviewer: So please tell us about it.
Proline: I really do want to get into it that much but um, WW and SH3 domains, which are protein-motifs, you know and I just basically bind to these two while they mediate protein-protein interactions by binding with a rich proline-ligand.
Interviewer: So are you the rich proline-ligand?
Proline: Maybe.(laughter)
Interviewer: Ok, so we are going to take a commercial brake, we’ll be be right back to talk more with Proline.
Interviewer: And we are back sitting here with Proline, who is an amino acid and an imino acid. So let’s get into it.
Interviewer: So who are you dating right now, I have been hearing rumors that it is non other than Glycine, please confirm.
Proline: Yes . “laughs”
Interviewer: Can I ask how did you meet?
Proline: we met in Collagen, right, you know where Collagen is, and we were introduced and we just hit it off my cousin um, hyroxyproline was there hanging out with us and, well we still hang out to this day.
Interviewer: That is so sweet, but I heard it was ARGININE, yes Arginine that introduced you two.
Proline: Yep.
Interviewer: What is it that you like about her?
Proline: Compared to the other amino acids, she is not optically active, she is not chiral at all and she is non-polar and has a aliphatic R group just like me.
Interviewer: Awwwww, well congrats I hope it works out for the best. Just one more question, though, is it true that you and Glycine are not welcome in to the Alpha Helix club.And for those of you, who don’t know Alpha-Helix is a secondary protein structure, very popular place, where a lot of amino acids hang out, well except Gly and Pro.
Proline: Yes, we are no longer welcome there.
Interviewer: Please explain.
Proline: Well you see, since I can form a five membered ring, my Nitrogen carbon- alpha bond cannot rotate and I kinda introduced a destabilizing kink in the structure. Well you know that the Alpha helix, uses hydrogen for all its bonding purposes, if you know what I mean. So my nitrogen group has no hydrogen to contribute to the bonding.
Interviewer: Wow, you cause a lot of damage. How about Glycine? How did she get in trouble, was it because she was with you.
Proline: She has high conformational flexibility because she has only hydrogen as her R group and that is why she is not chiral because you have to have a COO- , a NH3+, a H and some other group which is your R group and it has to be different from what I just called out there. You have to have four different groups around your central carbon o be called chiral.
Proline: So because of this she tends to form more turns because of the extra hydrogen and that’s not good for Alpha Helix.
Interviewer: From the sound of it both of you aren’t good for Alpha Helix.
Interviewer: So, thank you very much for joining us and we hope to see you again soon.
Proline: Thank You, Thank You, Always a pleasure.
So that’s it you guys my exclusive interview with Proline! See you soon!!!!!
References
European Molecular Biology Oraganization. 2013. “FBP WW domains and the Abl SH3 domain bind to a specific class of proline-rich ligands”. The Embo Journal (1997).Date Accessed April 13th, 2013.
In Bioinformatics for Geneticists, M.R. Barnes, I.C. Gray eds, Wiley, 2003. Date Accessed April 13th, 2013.
M.J. Betts, R.B. Russell. Amino acid properties and consequences of subsitutions.
Peaks6.2000-2013.”The Amino Acid Chart”.IonSource.Last Updated September 1st, 2012. Date Accessed April 13th, 2013.http://www.ionsource.com/virtit/VirtualIT/aainfo.htm
Picture links: http://www.blogography.com/photos35/Wayne05.gif
http://www.chem4kids.com/files/aminoacids/art/proline.gif
biochemaddict21 
