nucleotide chemistry and biochemistry at slu
DESCRIPTION
1. Nucleotide Chemistry and Biochemistry at SLU. Michael B. Doughty Associate Professor of Biochemistry Department of Chem & Phys Southeastern Louisiana University. 2. Representative Nucleotides. 5’. 3’. 3. DNA Synthesis by Polymerase. DNA Pol. DNA template. DNA template. 3’. 5’. - PowerPoint PPT PresentationTRANSCRIPT
Nucleotide Chemistry and Biochemistry at SLU
Michael B. DoughtyAssociate Professor of Biochemistry
Department of Chem & PhysSoutheastern Louisiana University
1
Representative Nucleotides
-O
N
NN
N
NH2
OOPO-
O-O
N
NN
N
NH2
OOPO-
O
OHOH OH
2'-deoxynucleotide 5'-phosphate (DNA form)
nucleotide 5'-phosphate (RNA form)
2'-deoxyribosesugar
base(purine)
phosphate ester
ribose sugar
5’
3’
2
DNA Synthesis by Polymerase
DNA template
DNA primer3’-OH
dNTP PPi
DNA template
DNA primerO-N-3’-OH
Inhibitors of DNA polymerase are traditionally used as anti-metabolites to treat cancer and DNA virus infections (e.g., Herpes simplex I and II; Cytomegalovirus; Hepatitis B virus, etc.)
3’ 5’DNA Pol
(repeat)
5’
3’ 5’
5’
3
N
NN
N SO
NH2
HO
N3
O
OPOPOPO-O
O-
O
O-
O
O-
template binding region
sugar binding region
triphosphate binding region
minor groove subsituent added to stabilize binary Pol-dNTP complex
Novel Template-Competitive DNA Polymerase Inhibitors
Doughty & Moore, 1996
4
DNA Synthesis by Reverse Transcriptase
Reverse transcriptase (RT) is a retroviral enzyme required for incorporation of a viral RNA genome into host DNA
RNA RNART
DNA
RT
RTDNA
DNA
DNA Integration and viral particle production
RT inhibitors are or could be used to treat retroviral disease (HIV; Hepatitis A and C; Rabies virus; Mumps and Influenza viruses)
5
Template-Competitive RT Inhibitors
N
N N
O
HO
S
O
R
NH4O9P3O
triphosphate binding pocket
2'-deoxyribose binding pocket
minor groove subsituent added to stabilize binary RT-dNTP complex
lipophilictemplatebinding pocket
N
Required base modifications for RT inhibition
Doughty, Li, & Lin, 2001
6
Structural Comparison of RT and DNA Pol Inhibitors
Conformationally, the etheno group forces a population where the side chain is bent under the sugar
DNA Pol TC inhibitors RT inhibitors
7
GTP Binding Proteins (G-Proteins)
8
GDP
activation
GTP GDP
GTP
activates cell processes:nerve conductionmetabolismsecretionreplication
+
H2O
Pi
GDP
Conformational Probes of G-Proteins
Seifert & Doughty, unpublished
9
Techniques
1. Chemical synthesis of nucleotides.
2. Conformational analysis of nucleotides and enzyme/protein binding sites.
3. Kinetic analysis and other bioassays.
10