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10, 000
MIT June 2010
OEIT Star BioChem (LA and KMV)
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10, 000 DNA lesions
X
1 trillion cells
10,000,000,000,000,000
MIT June 2010
OEIT Star BioChem (LA and KMV)
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DNA damage leads to mutations
MIT June 2010
OEIT Star BioChem (LA and KMV)
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DNA damage leads to mutations
1) toxic chemicals
(industrial & environmental)
5) UV rays
(sun)
MIT June 2010
2) X-rays
(clinic)
4) oxidation
(respiration, smoking)
3) viruses
(HPV)
OEIT Star BioChem (LA and KMV)
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DNA damage leads to mutations
toxic chemicals
(industrial & environmental)
X-rays
(clinic)
mutations
UV rays
(sun)
oxidation
(respiration, radiation, smoking)
MIT June 2010
disease
viruses
(HPV)
OEIT Star BioChem (LA and KMV)
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Oxidation can cause mutations in DNA
MIT June 2010
OEIT Star BioChem (LA and KMV)
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Oxidation can cause mutations in DNA
MIT June 2010
OEIT Star BioChem (LA and KMV)
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Oxidation can cause mutations in DNA
MIT June 2010
OEIT Star BioChem (LA and KMV)
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DNA glycosylase proteins help repair DNA
damage caused by oxidation
DNA glycosylases
MIT June 2010
OEIT Star BioChem (LA and KMV)
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Today’s activity: explore DNA glycosylases with
Star BioChem (You can find it online too!)
human
hOGG1
(37 °C)
MIT June 2010
archeabacteria
Pa-AGOG
(100 °C!)
OEIT Star BioChem (LA and KMV)
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Proteins perform many important
biological functions
hemoglobin
carry oxygen
in the blood
MIT June 2010
F1 ATPase
generate energy
antibody
protect against
infections
OEIT Star BioChem (LA and KMV)
microtubules
cell division
aquaporin
water transport
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Protein Data Bank website
The function of a protein is
determined by its structure
structure
MIT June 2010
function
OEIT Star BioChem (LA and KMV)
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These two proteins both fix the same DNA defect.
human
hOGG1
archeabacteria
Pa-AGOG
Protein Evolution:
1) Proteins with similar functions tend to have similar 3D structures.
2)
Proteins with similar 3D structures DO NOT ALWAYS have exactly the
same amino acid sequence. The folding is important for function.
MIT June 2010
OEIT Star BioChem (LA and KMV)
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Amino Acids
Identify the amino group, the acid group, and
the side chains. The side chains are also called “R groups” (R = residues)
Hydrophobic YELLOW
(Polar) Hydrophilic GREEN
Acid RED
Base BLUE
MIT June 2010
OEIT Star BioChem (LA and KMV)
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