Transcript Document

Study Guidelines for Chemistry
in Chapters 1 and 2
• Look at the slides that follow containing the list
of reactions on which to focus.
• Re-read the indicated pages where each reaction
is described in Creighton. Look at related power
point slides and examples discussed in class.
• Put together a summary sheet with each reaction
in as much detail as presented in Creighton or in
class and explain how it is used.
Reactions in Chapter 1
1) Coupling of carboxyl groups to amines catalyzed by
carbodiimides
Pg 8
A critical step in peptide synthesis is the activation of the
carboxyl group for nucleophilic attack by an amine and
consequent formation of a peptide bond. This activation can
be achieved in a variety of ways - see examples on pg 44.
In the example of peptide synthesis presented in class the
carboxyl group was activated by reaction with a
carbodiimide. Another example is given on pg 46 Creighton.
Summarize this reaction in the context of one full round of
peptide synthesis.
2) Reaction of Cys with iodoacetate
pg 17
3) Irreversible oxydation of Cys with performic acid
pg 18
4) Disulfide bond formation between Cys residues and reaction
with reducing agents.
pg 19 and 98
5) Reaction of amino acids with reagents to produce strongly
absorbing or fluorescent compounds:
a) ninhydrin
b) fluorescine
c) o-phthalaldehyde
pg 21 and 22
6) Determination of amino terminal residue.
pg 31 and power point slide
Reaction with:
a) fluoro-2,4-dinitrobenzene
b) dansyl chloride
7) The Edman degradation reaction
pg 33 and class notes
8) Cleavage of peptides after Met by reaction with
CNBr
pg 39
Reactions in Chapter 2
N and C-terminal modifications:
9) Acylation of the N-terminus
pg 87
10) Myristoylation of the N-terminus
pg 88
11) Glycosyl-phosphatidylinositol anchor at C-terminus
pg 89
12) Farnesylation of C-terminus
pg 90 and following slide
Farnesylation at C-terminal CAAX motif in Ras
The reaction occurs at the Cys residue
13) Amidation of C-terminus in hormones containing
C-terminal Gly residue
pg90
Sidechain modifications:
14) Glycosylation – pgs 91-93
N-glycosylation of Asn – pg 91
O-glycosylation of Ser, Thr and Hyl – pg 93
15) Lipid attachment
pg 94 example of palmytoylation of Cys residues
reactions at terminals, 11 and 13 above, are also lipid
attachments
16) Phosphorylation
pg 96-97
S, T, Y
H, K, D
17) ADP-ribosylation
pg 98
H, R, N, K, E
18) Disulfide bond formation
pg 98-99