AMINO ACIDS

1

AMINO ACIDS
H
NH2 C COOH

R

NH3 CHR COO
2

AMINO ACIDS
3

AMINO ACIDS

2 ISOMERIC FORMS
D- L- Sterioisomers
4

Dehydration Rx
H2O

L-Amino Acids
5

Classification of Amino Acids

Aliphatic Hydroxyl Aromatic Acidic Basic Sulfur S
elenium Secondary Hydroxylated
6

7

Titration of Alanine

pI 6.0
pK 2 9.7
pK 1 2.3
8

pK 3 9.9
Titration of Glutamic Acid

pK 2 4.3
pK 1 2.2
pI 3.2
9

10

11

Bioactive
Amino Acids
12

Modified Amino Acids

13

Peptide Bond

14

Polypeptide

n-1 peptide bonds
15

Bioactive
Polypeptides

16

Glutathione
Redox RX 2GSH GSSG
17

Oxytocin
COOH !
18

• v

Proteins
MW 5000
19

Types of Proteins
1. Enzymes-biological catalyst 2.
Immunoglobulins-antibodies 3. Transport
proteins-ie. hemoglobin 4. Hormones- insulin,
glucagon 5. Structural proteins-keratin,
collagen, elastin
6. Contractile proteins-actin and myosin 7.
Compound Proteins Metalloproteins-ferritin Lipopro
teins-HDL, LDL Glycoproteins-glycophorin A
20

21

Bond

Backbone
Spacefil
Ribbon
22

Protein Structure
1. Primary Protein Structure 2. Secondary Protein
Structure 3. Tertiary Protein Structure 4.
Quaternary Protein Structure
23

Primary Protein Structure
The order of the amino acids in the peptide array
NH3-ala-gly-phe-ser-tyr-etc...etc....etc..ile-COO
-
Alyanylglycinylphenyalanylserinyltrrosiyl......iso
leusine
24

Primary Protein Structure

gt 50 AA Protein
n-1 petide bonds
25

Secondary Protein Structure
Formation of the Alpha Helix and Hydrogen bonding
26

Alpha Helix
Secondary Protein Structure
27

B-pleated Sheet

28

B-pleated Sheet

29

B-pleated Sheet

30

Antiparallel

Parallel
31

Tertiary Protein Structure

Formation of folded protein consisting of
1. Disulfide bridges 2. Electrostatic forces 3.
Hydrophobic interactionsinteractions 4.
Additional H-bonding
32

Secondary Structure Tertiary Structure

33

Quaternary Protein Structure
The association of protein subunites either
similar or dissimilar, ie hemoglobin
beta chain
alpha chain
34

Proteins
35

Erythrocytes
36

Hemoglobin
Heme

37

Alpha Chain Sequence

214 Residues
38

Beta Chain Sequence

214 AA Residues
39

Prosthetic Group
Heme
Red
Binds O2 Binds CO2 Binds CO
Blue
Cherry Red
Binding to O2
CO gtgt O2 gt CO2
40

Heme

41

Heme and Oxygen

42

Hemoglobin
43

Hemoglobin
44

Heme and Oxygen

45

Conformational Change

46

Oxyhemoglobin
47

Insulin

48

All Same
Beef, Pork Human, Recom

Human Mutants
Lantus
Beef
Beef Pork
Humalog Novalog
49

Glutathione Reductase
50

Cytochrome c
Cytochrome c Peroxidase
51

Thioredoxin Reductase
52

53

Glycophorin A
54

Protein Conformation
1. Native State 2. Denatured State 3. Hydrolyzed
State 4.Crystalized State
Denaturation destroys the secondary and tertiary
protein structure
Hydrolysis causes the release of the amino acids
from peptide linkage
55

X-Ray Sectroscopy

56

Amino Acids and Proteins
The End