CHM3930 Lecture Notes - Lecture 4: Polystyrene, Nucleophilic Acyl Substitution, Chief Operating Officer
20 Jun 2018
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Week 4 -Topic 3
Solid phase peptide synthesis (SPPS)
can make new proteins
Can substitute one amino acid at a time to determine which ones are involved in the
reaction, or which ones can be replaced with a different amino acid for better biological
activity.
Synthesise important peptides (ie. Insulin, vaccines)
Amino acids
α-Carbon – bonded to NH2, COOH, H, and R-group
Synthesis: CN; Nature: NC
oAttach COOH end to linker which attaches to resin
When making chains, need to ensure R-group does not take part in reaction
oProtecting groups strategy -masking the reactivity of a group
– Easy to put on
– Withstand the reaction conditions the amino acid is subjected to
– Easy to take off
NH2: use Fmoc p.g.s. -base sensitive
R-groups: use acid sensitive p.g.s.
Solid phase attached to COOH
Done under basic conditions
Acid wash used to remove p.g.s. & to detach protein from resin
– Note that if reaction conditions go slightly acidic, then the p.g.s. will
fall off before completion of reaction, and final product won’t be
right
Solid phase
oResin phase -gives a good yield
oCan be little balls of polystyrene
oWill swell or shrink depending on what solvent they are exposed to
Swollen most useful, as SA and reactive functional groups are exposed
o***REMEMBER STRUCTURES OF THREE RESINS FROM PPT
Linker – takes resin (solid phase) and the first amino acid
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Solid phase peptide synthesis (spps) can make new proteins. Can substitute one amino acid at a time to determine which ones are involved in the reaction, or which ones can be replaced with a different amino acid for better biological activity. Carbon bonded to nh2, cooh, h, and r-group. Synthesis: c n; nature: n c: attach cooh end to linker which attaches to resin. When making chains, need to ensure r-group does not take part in reaction: protecting groups strategy -masking the reactivity of a group. Withstand the reaction conditions the amino acid is subjected to. Note that if reaction conditions go slightly acidic, then the p. g. s. will fall off before completion of reaction, and final product won"t be right. Solid phase: resin phase -gives a good yield, can be little balls of polystyrene, will swell or shrink depending on what solvent they are exposed to.
