Biological Molecules — Introduction • proteins: amino acids protein

184 Pages·2006·3.73 MB·English

Page 9
Biological Molecules — Introduction
• proteins: amino acids
protein folding, binding
synthesis
catalysis
cofactors
• nucleic acids: DNA
RNA
carcinogens, drugs
• carbohydrates: simple
oligosaccharides
• “small molecules”: natural products
Page 10
STRUCTURE
AND
CHEMISTRY
OF
PROTEINS
Page 11
The Structure and Chemistry of Proteins
Amino acids
• hydrophobic amino acids
H3C CH H3C
3
CH H
3
H3C H H3C H H H3C H
O O O O
H3N H3N H3N H3N
O O O O
alanine/Ala/A valine/Val/V leucine/Leu/L isoleucine/Ile/I
OH
CH
NH 3
S
H H H H H
O O O O O
H N H N H N H N N
3 3 3 3
O O O O H2 O
phenylalanine/Phe/F tryptophan/Trp/W tyrosine/Tyr/Y methionine/Met/M proline/Pro/P
• polar amino acids
OH H OH
H H H H3C H
O O O
H3N H3N H3N
O O O
glycine/Gly/G serine/Ser/S threonine/Thr/T
O
O H N
2
SH NH2
H H H
O O O
H3N H3N H3N
O O O
cysteine/Cys/C asparagine/Asn/N glutamine/Gln/Q
• charged amino acids
NH
2
H3N H2N
O NH
O O HN NH
O
H H H H H
O O O O O
H N H N H N H N H N
3 3 3 3 3
O O O O O
aspartate/Asp/D glutamate/Glu/E lysine/Lys/K arginine/Arg/R histidine/His/H
Page 12
The Structure and Chemistry of Proteins
Conformational analysis of small molecules
sp3-sp3 bonds: A quick review
• ethane
• butane
Page 13
Conformational analysis of small molecules — continued
• pentane
Page 14
Conformational analysis of small molecules — continued
• cyclohexane
Page 15
The Structure and Chemistry of Proteins
Conformational parameters of peptides
• Valine (Val, V)
• Leucine (Leu, L)
Page 16
Conformational parameters of peptides — continued
• Isoleucine (Ile, I)
• Methionine (Met, M)
Page 17
A role for methionine flexibility in biology
Page 18
Conformational parameters of peptides — continued
sp2-sp3 bonds
• propene
• substituted propene
• peptide (amide) bond