Flashcards in Amino Acids, Peptides, and Protein I Deck (45)
Hydrophobic and non-polar amino acids
(LIMP- TV Channel)
hydrophilic and polar amino acids
acidic amino acids
basic amino acids
what may interactions between positive and negative R groups form?
salt bridge important for stabilization in proteins
what is a disulfide bond?
covalent linkage between two sulfer atoms specifically between cystine residues (thiol groups)
which amino acid has a sulfur bond but cannot participate in a disulfide bond?
where are disulfide bonds usually found within a folded protein?
on the inside because they are hydrophobic
what are the 6 major post-translational modifications that we need to know?
1. hydroxylation of proline
2. carboxylation of glutamate
3. modification by acetylation or methylation
5. reversible phosphorylation/dephosphorylation
what adds a hydroxyl group to proline residue?
what is the predominate secondary structure in collagen and how is it formed?
formed by multiple prolines and hydroxyprolines in a row
what is the cofactor of prolyl hydroxylase?
what disease results as a lack of vitamin C and which structure is affected?
scurvy, loss of integrity in connective tissues becase lack of proline hydroxylation
which enzyme adds a carboxyl group to the side chain of glutamate?
what is the co-factor of carboxylation of glutamate?
where is carboxylation of glutamate mostly found?
within clotting factors
what will a lack of vitamin K cause in regards to carboxylation of glutamate?
how does waafarin work?
blood thinner that prevents clotting by inhibiting activity of gamma-glutamyl carboxylase
where does acetylation by HATs usually occur?
lysine residues of free tails of histones
where does methylation usually occur and by which enzyme?
lysine and arginine residues on histones by methyltransferases
what type of inhibitor is Vorinostat?
what is the mechanism of Vorinostat?
prevents removal of acetyl groups from histones. Tumors usually use deacetylation to repress tumor suppresor genes.
what is glycosylation?
attaching glycans (sugars) to proteins
what are the 4 types of glycans?
1. N-linked glycans
2. O-linked glycans
4. C-linked glycans
what amino acids to N-linked glycans attach to?
asparagine and arginine side chains
what amino acids to O-linked glycans attach to?
serine, threonine, tyrosine, hydroxylysine, hydroxyproline side chains
where do phospho-glycans attach?
phosphate of phospho-serine
where do C linked glycans attach?
carbon on tryptophan side chain
True of False
Glycosylation makes protein more polar