Will India Become Superpower in 2020
Peptide synthesis – chemistry and modifications
Peptides and proteins exhibit the largest structural and functional variation of all classes of biologically active macromolecules. Biological functions as diverse as sexual maturation and reproduction, enzyme inhibition, blood pressure regulation, glucose metabolism, thermal control, analgesia and learning and memory are now thought to be regulated by peptides.
Peptide synthesis chemistry
Synthetic peptides are valuable tools in analysis of naturally occurring peptides or proteins. Since Emil
Fischer’s pioneering work in the early 1900’s, synthesis methods have improved continually – especially with Merrifield’s development of solid-phase syntheses.
Besides the classical synthesis in solution, solid-support synthesis is now the most widely used method to prepare synthetic peptides. The advantages of solid-support synthesis are its speed, versatility, ease of automation and low costs.
However, peptide chemistry still remains a difficult and exacting science.
Solid-phase synthesis is usually carried out as follows:
1.
2.
3.
4.
5.
loading of C-terminal amino acid to resin (not shown below) deprotection: removal of N-terminal protecting group (PG) at amino residue activation of next amino acid at carboxy residue coupling reaction start synthesis cycle 2-4 again or cleave fully-synthesised peptide off resin
R
H
N
C
PG
H
C
H
R
N
OH
PG
activation
N
PG
C
C
O
C
O
H
deprotection
R
H
O
C
N
OH
H
R
H
O
H
C
H
O
etc.
C
O
coupling
R
H
N
PG
O
C
C
H
R
N
C
H
H
O
O
removal H
R
H
C
N
O
C
C
H
R
N
C
H
H
O
C
OH
1
Protecting groups (PGs)
One of the demanding parts in peptide synthesis is the necessity to block those functional groups that must not participate in peptide bond formation. Such “protecting groups” are needed for
Peptides and proteins exhibit the largest structural and functional variation of all classes of biologically active macromolecules. Biological functions as diverse as sexual maturation and reproduction, enzyme inhibition, blood pressure regulation, glucose metabolism, thermal control, analgesia and learning and memory are now thought to be regulated by peptides.
Peptide synthesis chemistry
Synthetic peptides are valuable tools in analysis of naturally occurring peptides or proteins. Since Emil
Fischer’s pioneering work in the early 1900’s, synthesis methods have improved continually – especially with Merrifield’s development of solid-phase syntheses.
Besides the classical synthesis in solution, solid-support synthesis is now the most widely used method to prepare synthetic peptides. The advantages of solid-support synthesis are its speed, versatility, ease of automation and low costs.
However, peptide chemistry still remains a difficult and exacting science.
Solid-phase synthesis is usually carried out as follows:
1.
2.
3.
4.
5.
loading of C-terminal amino acid to resin (not shown below) deprotection: removal of N-terminal protecting group (PG) at amino residue activation of next amino acid at carboxy residue coupling reaction start synthesis cycle 2-4 again or cleave fully-synthesised peptide off resin
R
H
N
C
PG
H
C
H
R
N
OH
PG
activation
N
PG
C
C
O
C
O
H
deprotection
R
H
O
C
N
OH
H
R
H
O
H
C
H
O
etc.
C
O
coupling
R
H
N
PG
O
C
C
H
R
N
C
H
H
O
O
removal H
R
H
C
N
O
C
C
H
R
N
C
H
H
O
C
OH
1
Protecting groups (PGs)
One of the demanding parts in peptide synthesis is the necessity to block those functional groups that must not participate in peptide bond formation. Such “protecting groups” are needed for