Amino Acids

Alanine Abbreviations

Ala or A

Arginine Abbreviations

Arg or R

Asparagine Abbreviations

Asn or N

Aspartic Acid Abbreviations

Asp or D

Cysteine Abbreviations

Cys or C

Glutamic acid Abbreviations

Glu or E

Glutamine Abbreviations

Gln or Q

Glycine Abbreviations

Gly or G

Histidine Abbreviations

His or H

Isoleucine Abbreviations

Ile or I

Leucine Abbreviations

Leu or L

Lysine Abbreviations

Lys or K

Methionine Abbreviations

Met or M

Phenylalanine Abbreviations

Phe or F

Proline Abbreviations

Pro or P

Serine Abbreviations

Ser or S

Threonine Abbreviations

Thr or T

Tryptophan Abbreviations

Trp or W

Tyrosine Abbreviations

Tyr or Y

Valine Abbreviations

Val or V

What amino acid is this?

Proline

What amino acid is this?

Threonine

What amino acid is this?

Serine

What amino acid is this?

Methionine

What amino acid is this?

Cysteine

What amino acid is this?

Glutamine

What amino acid is this?

Asparagine

What amino acid is this?

Glutamic Acid

What amino acid is this?

Aspartic Acid

What amino acid is this?

Histidine

What amino acid is this?

Arginine

What amino acid is this?

Lysine

What amino acid is this?

Tryptophan

What amino acid is this?

Tyrosine

What amino acid is this?

Phenylalanine

What amino acid is this?

Isoleucine

What amino acid is this?

Leucine

What amino acid is this?

Valine

What amino acid is this?

Alanine

What amino acid is this?

Glycine

What is proline known to do?

-disrupt alpha helices

-because of its set angle it does beta turns

What are the redox signals? Which is better than the other and why?

methionine and cysteine

methionine is the primary redox signal because it can go back and forth between its reduced and oxidized state in response to oxidizing envronments. cysteine is not ideal because it can oxidize twice, the second of which is not reversible so it will kill the protein/enzyme in highly oxidative environments

What amino acids do pi stacking? What is it used for?

typically phenylalanine and tryptophan

the side chains for these are considered non polar but the electron pi system is slightly polar and needs to be stabilized in a completely nonpolar environment. pi stacking is done to help stabilize these electrons

Which amino acids are beta branched?

isoleucine, valine, and threonine

What is cysteine good for?

making disulfide bonds (cystine)

good and easily made nucleophile (because pka is within 1 of physiological pH)

Which amino acid is gamma branched?

leucine

What is the main thing that aspartic acid and glutamic acid do?

They are in basic form in the body, so they give a natural negative charge and are great H bond acceptors

**they don’t act as acid/base in the body except in a lysosome where the environment is so acidic

What is histidine good to do?

acid base catalysis

okayyy nucleophile in base form but this is rare

Which amino acids are aromatic?

phenylalanine, tyrosine, and tryptophan

Nucleophiles

-cysteine is the best one that is typically going to be used

-serine and lysine are good but they are hard to make

-histidine is an okayyy nucleophile

Electrophiles

-there are no natural electrophiles

-the closest are aspartic and glutamic acids since an enzyme can be used to put a LG in place of the oxygen which would then make it a good electrophile

What amino acids can be phosphorylated? Which are stable/unstable? What is the purpose?

-anything with an -OH can be phosphorylated and is stable (serine, tyrosine, threonine). these are used for regulation

-cysteine, aspartic acid, and glutamic acid can be but they are unstable. these are used for timing mechanisms since they won’t stay phosphorylated long