compounds that interfere with calcium signaling
- domoic acid
- methylmercury
- detergents
compounds that interfere with oxidative phosphorylation
- DDT
- PCP
- cyanide
- cocaine & other alkaloids
- ethanol
ABC transporters stands for
ATP-binding cassette transporters
-unusual in their ability to harness cell’s energy directly
solute carrier transporters
-use concentration gradient to move things or energy stored in membrane potential, they don’t require direct energy hydrolysis
different families of transporters
ABCA, ABCB, ABCC, ABCD, ABCE, ABCF, ABCG, ABCH
3 families of transporters relevant to drug disposition
ABCB, ABCC, ABCG
ABCB
- 12 transmembrane spans
- 2 nucleotide binding domains
- likes small, hydrophobic molecules
- transports in their unmodified state
- transports them as soon as they enter the membrane, before they even enter the cell
- main reason for drug resistance for leukemia
nucleotide binding domains (NBDs)
hydrolyze ATP to ADP and uses that energy to pump the molecule against the concentration gradient
ABCC
- 17 transmembrane spans
- 2 nucleotide binding domains
- only one to transport modified compounds (ex: metals conjugated to glutathione)
ABCBs are found in…
gills, liver, kidneys, brain
ABCCs are found in…
lungs, liver
ABCGs are found in…
mammary tissue (secreting into the milk), liver
ABCG
- 6 transmembrane spans
- 1 nucleotide binding domain
- need two of these to make one transporter
- transports plant metabolites (ex: alkaloids)
- hydrophobic, small molecules
bioremediation
- using biology to mitigate effects of pollutants in the environment, often deployed after catastrophic events
- EX: oil spills, acid pit (dump site)
- can use microorganisms or plants or animals, bacteria often used
Comprehensive Environmental Response Compensation and Liability Act - Superfund 1980
- more than 1500 sites in the US
- greatly contaminated sites
Contaminants can be removed from groundwater using…
activated carbon
migration control
physical “caps” and barriers to prevent mixing
erosion control
shallow rooted plants will help prevent natural processes from deteriorating the barriers
biotic barrier
a layer of stones to prevent animals from burrowing into the waste
plastic membrane and clay with low adhesion properties
hard, heavy physical barrier pushing the waste down
biological methods of remediation
- phytoremediation
- microbial degradation
- fungal remediation
- molluscs and filter feeders
- GMOs
abiotic methods of remediation
- adsorption to carbon
- photolysis
- precipitation
- physical removal/dredging
- volatilization
bacteria as a bioremediator
PROS
-grow rapidly if food is present
-critical for emulsification of oil
CONS
-growth limited by nutrients/physical factors
-not everything can be degraded
-degraded products are sometimes more toxic
phytoremediation
- can involve breakdown or sequestration
- on land
- using plants to remove contaminants by volatilizing them, sequestering them within the plant, or promoting biodegradation in the soil
