Ch_322b_24.08

Ch_322b_24.08 - Polypeptide and Protein Synthesis There are...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Polypeptide and Protein Synthesis There are two general problems that must be addressed in the synthesis of polypeptides from amino acids: Directed Coupling The synthesis of a dipeptide by the coupling of two amino acids illustrates this problem. Since amino acids are bifunctional , coupling can occur to produce two different mixed dipeptides. The possibility of an amino acid coupling with itself is an additional problem. directed coupling of the bifunctional amino acids racemization of the chiral amino acids H 2 NCHCOOH R + H 2 NCHCOOH R' H 2 NCHC NHCHCOOH R R' O = + H 2 NCHC NHCHCOOH R' R O A B
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Directed coupling is achieved by using a protecting group (Q) to block reaction at one of the nucleophilic amino groups. Q HNCHCNHCHCOOH R R' O = removal of Q H 2 NCHC NHCHCOOH R R' O There are two widely used protecting groups for polypeptide synthesis. Both function by eliminating the nucleophilic character of the amino group. Good protecting groups are easy to put on and easy to take off. directed coupling
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/23/2011 for the course CHEM 322BL taught by Professor Singer during the Spring '07 term at USC.

Page1 / 7

Ch_322b_24.08 - Polypeptide and Protein Synthesis There are...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online