Typical%20approaches%20in%20classical%20peptide%20synthesis:

1
Typical approaches in classical peptide
synthesis segment condensation
2
Typical approaches in classical peptide
synthesis stepwise elongation
A) C-terminal stepwise elongation
CO-X
Q - NH
CO Q,
CO Q,
Q - NH
B) N-terminal stepwise elongation
CO-Q,
Q -NH
CO-X
CO-Q,
Q -NH
N-terminal deprotection
CO-Q,
Q -NH
CO-X
etc.
3
Bruce R. Merrifield
4
The Origins
There is a need for rapid, quantitative,
automatic method for the synthesis of long
peptides. A possible approach may be the use of
chromatographic columns Where the peptide is
attached to the polymer packing and added to by
an activated amino acid followed by removal of
protecting group, with repetition of the
process Until the desire peptide is built up.
Finally the peptide must be removed from the
supporting medium.
R.B.Merrifield Laboratory note book
(1959) JACS 85, 2149
(1963)
5
The solid phase principle
Anchor
Functionalize
Resin
Resin
.
X
Resin
Couple
.
Resin
S
COOH
S
Cleave, purify
Elongate
.
.
.
Resin
Target peptide
.
.
.
6
Essetial aspects of solid phase peptide synthesis
A. The solid support
B. The protection scheme
A combination of protecting groups (N-, C-, side
chains) that ensures
1. Peptide-polymer bond stable during synthesis
2. Temporary protection of the a-amino group
3. Permanent protection of the side chains
4. Efficient cleavage with simultaneous side
chain removal
7
Solid phase synthesis on polystyrene-divinylbenzen
e
X
Functionalize
Anchor
X
X
Carboxyl activation
Repeat, n times
1,4-divinylbenzene
Cleave, purify, etc...
Q N-terminal amino-protecting group
8
Protection in solid phase synthesis
b
c
a
R
9
Boc/benzyl chemistry - Merrifield method
P
OCO-NH
CH
CO
O
10
Robert C. Sheppard
11
Fmoc/t-butyl chemistry - Sheppard method
H
OCO-NH
CH
CO
P
O
Labile to TFA
P
Cl
P
CH
O
Cl
Fmoc
NH
2-chlorotrityl resin
HOAc/free acid
HOAc, dilute TFA/amide
12
Linear solid phase synthesis
13
Convergent solid phase synthesis
14
Solid-Phase Synthesis of Peptides A Summary
Solid phase
Fully protected
Functionalized
peptide synthesis
peptide-resin
polymer
deprotection

peptide-resin
cleavage
AAA
HPLC
purification
Crude free peptide
Characterization
HPCE
Purified peptide
enzyme digestion
MS
(control by HPLC, AAA, etc.)
What can I expect to find in a synthetic peptide
crude ?
The desired peptide (!)
Ac-DEFGHIK
Deprotection scavengers
Terminated
Ac-HIK
Non-peptide
Wrong peptides
Protecting group derivatives
Peptide
ABCDEFHIK (minus G)
Anything else...
ABCDFGHIK (minus E)
Deleted
ABCEFGHIK (minus D)
ACDEFGHIK (minus B)
Incompletely deprotected peptide products
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Combinatorial synthesis portioning-mixing
principle
Furka et al. Int. J.Pept. Prot. Res. (1991)
T- R
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9
8
10
12
11
1
3
2
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6
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19
13
15
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Y
A
D
E
F
G
H
I
K
L
M
N
P
Q
R
S
T
V
W
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9
8
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11
1
3
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5
19
13
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X
1
T- R
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9
8
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3
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19
13
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18
Y
A
D
E
F
G
H
I
K
L
M
N
P
Q
R
S
T
V
W
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9
8
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11
1
3
2
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6
5
19
13
15
14
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X2X1T -
R
X2X1T
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Combinatorial synthesis of TX1TX2T peptide library
18
Paralell synthesis of TQTX2T peptide sub-library
T- R
7
9
8
10
12
11
1
3
2
4
6
5
19
13
15
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14
Y
A
D
E
F
G
H
I
K
L
M
N
P
Q
R
S
T
V
W
7
9
8
10
12
11
1
3
2
4
6
5
19
13
15
14
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17
18
6
7
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8
10
12
11
1
3
2
4
5
19
13
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Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
Q
7
9
8
10
12
11
1
3
2
4
6
5
19
13
15
14
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17
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T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
A
D
E
F
G
H
I
K
L
M
N
P
Q
R
S
T
V
W
Y
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
19
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SPOT peptide synthesis
22
Applications
23
More applications
24
Néhány fontos peptid
Karnozin (N-b-alanilhisztidin)
Glutation
Oxitocin
Vazopresszin
25
Inzulin
Hasnyálmirigy hormonja A lánc B-lánc Izolálás
1922 Banting Primer Szerkezet 1953
Sanger Szintézis 1969 Zahn, Wang,
Katsoyannis Térszerkezet 1965 Hodgkin
ATCH
39 aminosav Sertés szintézis Schwitzer,
1963 Humán szintézis Bajusz, Kisfaludy,
Medzihradszky 1971