Test 4 Peptide Synthesis Flashcards
three letter and single letter codes for amino acids
know these
Basic strategies for peptide synthesis
Reactants → Protection → Activation → Synthesis
→ Deprotection
What are the blocking groups to protect alpha amino groups?
- Boc
- Fmoc
What are the blocking groups to protect alpha carboxyl groups?
- for SPPS: polystyrene / resin
- for solution: protected as an alkyl or aryl ester
What are amino groups converted into?
- alkoxycarbonylamino derivatives
- made up of amides and esters which leads to the inactivity
What is the Z group?
when an H at the amino group is converted into a Benzyloxycarbonyl group to protect it
How do you remove the Z group?
- synthesize Z group and peptide under basic conditions
- remove Z group under acidic conditions
- add Carbamic acid which spontaneously decarboxylates and gives back the amino group
What is Boc?
- amino group protector
- t-Butoxycarbonyl (Boc) protection
- more labile to acids than Z group
What is Fmoc?
- amino group protector
- 9-Fluorenylmethoxycarbonyl (Fmoc) protection
- stable under acidic conditions; cleaved under basic conditions
- deprotected with piperidine
What are protecting groups for alpha-amino?
Benzyloxycarbonyl (Z-)
What are protecting groups for epsilon-amino (Lys)?
t-Butoxycarbonyl (Boc-)
What are protecting groups for alpha-carboxyl?
Methyl, ethyl
What are protecting groups for B-Sulfhydryl (Cys)?
Benzyl (-SBzl)
What are protecting groups for Beta-OH (Ser, Thr)?
t-Butyl
What are protecting groups for Phenolic OH (Tyr)?
Benzyl
