Amino Acids, Peptides, and Protein I Flashcards Preview

M2M Biochemistry and molecular biology > Amino Acids, Peptides, and Protein I > Flashcards

Flashcards in Amino Acids, Peptides, and Protein I Deck (45):
1

Hydrophobic and non-polar amino acids

Valine
Isoleucine
Leucine
Methionine
Phenylalanine
Tryptophan
Cystine
(LIMP- TV Channel)

2

hydrophilic and polar amino acids

argenine
lysine
aspartate
glutamate
asparagine
glutamine

3

acidic amino acids

aspartate
glutamate

4

basic amino acids

lysine
arginine
histidine

5

what may interactions between positive and negative R groups form?

salt bridge important for stabilization in proteins

6

what is a disulfide bond?

covalent linkage between two sulfer atoms specifically between cystine residues (thiol groups)

7

which amino acid has a sulfur bond but cannot participate in a disulfide bond?

methionine

8

where are disulfide bonds usually found within a folded protein?

on the inside because they are hydrophobic

9

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
4. glycosylation
5. reversible phosphorylation/dephosphorylation
6. ubiquination

10

what adds a hydroxyl group to proline residue?

prolyl hydroxylase

11

what is the predominate secondary structure in collagen and how is it formed?

proline helix
formed by multiple prolines and hydroxyprolines in a row

12

what is the cofactor of prolyl hydroxylase?

vitamin C

13

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

14

which enzyme adds a carboxyl group to the side chain of glutamate?

Gamma-glutamyl carboxylase

15

what is the co-factor of carboxylation of glutamate?

vitamin K

16

where is carboxylation of glutamate mostly found?

within clotting factors

17

what will a lack of vitamin K cause in regards to carboxylation of glutamate?

hemorrhage

18

how does waafarin work?

blood thinner that prevents clotting by inhibiting activity of gamma-glutamyl carboxylase

19

where does acetylation by HATs usually occur?

lysine residues of free tails of histones

20

where does methylation usually occur and by which enzyme?

lysine and arginine residues on histones by methyltransferases

21

what type of inhibitor is Vorinostat?

HDAC inhibitor

22

what is the mechanism of Vorinostat?

prevents removal of acetyl groups from histones. Tumors usually use deacetylation to repress tumor suppresor genes.

23

what is glycosylation?

attaching glycans (sugars) to proteins

24

what are the 4 types of glycans?

1. N-linked glycans
2. O-linked glycans
3. phospho-glycans
4. C-linked glycans

25

what amino acids to N-linked glycans attach to?

asparagine and arginine side chains

26

what amino acids to O-linked glycans attach to?

serine, threonine, tyrosine, hydroxylysine, hydroxyproline side chains

27

where do phospho-glycans attach?

phosphate of phospho-serine

28

where do C linked glycans attach?

carbon on tryptophan side chain

29

True of False
Glycosylation makes protein more polar

true

30

what is the purpose of glycosylation?

- proper protein folding
- increased stability of secreted glycoproteins
- cell to cell adhesion
- role in recognition

31

what genetic disease does disruption in N-glycosylation lead to?

Congenital disorder of glycosylation (CDG)

32

what is the presentation of congenital disorder of glycosylation (CDG)?

developmental delay and hypertonia

33

what mutation causes congenital disorder of glycosylation (CDG)?

PMM2 gene, autosomal recessive

34

which amino acids does phosphorylation usually occur?

serine, threonine, tyrosine
phosphate group added to OH

35

what does phosphorylation do?

activates or deactivates proteins and does reverse with dephosphorylation

36

what is the target of Gleevac?

bcr-abl tyrosine kinase

37

what disease is Gleevac used to treat?

Chronic myelogenous leukemia (CML)

38

what is the mechanism of action of Gleevac?

kinase inhibitor: prevents bcr-abl tyrosine kinase from phosphoyrlating tyrosine by competitively binding to active site

39

what is the most common type of modification of amino acids in cells?

ubiquination

40

what is the function of ubiquination?

targets protein for destruction from the proteosome

41

what is the process of ubiquination?

adds ubiquitin to lysine residues, addition of one recruits several more

42

what disease does bortezomib treat?

multiple myeloma

43

what kind of drug is bortezomib classified as?

proteasome inhibitor

44

what is the mechanism of bortezomib?

boron atom in bortezomib binds to catalytic site of 26S proteasome with high affinity and specificity

45

what is the theory of proteasome inhibition?

prevents degredation of pro-apoptotic factors permitting programmed cell death in cells dependent on suppression of pro-apoptotic pathways