TETRAPHENYLPHOSPHONIUM BROMIDE (TPP) LARGE MOLECULE~SMALL MOLECULE INTERACTIONS

Pilgrim High SchoolMr. Dubois, Mr. LobdellC.J. Beneduce, Bryan Hallinan, Amanda Legare, Ed White

CHEMICAL COMPOUND

TPP: (C6H5)4P(Br) Molecular Weight: 419.31 AMU 2.86E-10 mole TPP/μl d. H20 Melting Point Range: 295 - 299°C Soluble in water Other physical properties and toxicity levels

not available Hazardous Decomposition Products: Carbon

monoxide, carbon dioxide, hydrogen bromide gas, thermal decomposition may produce toxic fumes of phosphorus oxides and/or phosphine.

GENOMIC DNA MELTING

45 50 55 60 65 70 75 80 85 90 95 1000.155

0.255

0.355

0.455

0.555

0.655

DNA + TPP: DNA, 1, 3, 5 µl

DNADNA + 1µl "TPP" DNA + 3µl "TPP"DNA + 5µl "TPP"

Temperature ˚C

Abso

rban

ce

GENOMIC DNA MELTING

45 50 55 60 65 70 75 80 85 90 95

-0.005

0

0.005

0.01

0.015

0.02

DNA Melting Point - Derivative Plot

Salmon DNA OnlyDNA - 1μl TPP

Average Temperature

delta

A/ d

elta

T

ELECTROPHORESIS Distance (mm)

2324262830*34445162

Number of Bases10,0008,0006,0005,0004,000*3,0002,0001,5001,000

According to the electrophoresis test, it appears that the cut plasmid

has 4,000 bases. This supports that the plasmid had no significant

effect on the DNA.

Ladder

*33nanoGrams (nG)(cf. Biolabs bulletin www.neb.com/nebecomm/products3232.asp)

HYPERCHEM PREDICTIONS4 BP DNA

Description Random Sequence

Test Program Orient. Energy Gradient Groove

DNA AMBER X n/a n/a n/a

DNA AMBER Y 14.286 0.094 Major

DNA AMBER Z 0.029 0.096 * Minor

12 BP DNA

Description Random Sequence

Test Program Orient. Energy Gradient Groove

DNA AMBER X -770.037 0.376 Major

DNA AMBER Y -779.271 0.364 Major

DNA AMBER Z 12.937 0.094 Major

HYPERCHEM PREDICTIONS

12 BP DNA

Description Random Sequence

Test Program Orient. Energy Gradient Groove

DNA MM+ X 11.778 0.088 Major

DNA MM+ Y 5.689 0.084 Major

DNA MM+ Z 6.424 0.094 Major

4 BP DNA

Description Random Sequence

Test Program Orient. Energy Gradient Groove

DNA MM+ X n/a n/a n/a

DNA MM+ Y 18.123 0.083 Major

DNA MM+ Z 20.350 0.091 Major

• For all optimization Polak Ribiere was used• Both AMBER and MM+ were used

DISCUSSION HyperChem analyses led to the prediction

that Tetraphenylphosphonium Bromide would bond with DNA. The experimental results contrasted with this prediction. According to the results of the electrophoresis and the melting curve, TPP did not have an impact on the DNA molecule.

Dr. Williams et al performed related experiments, including electrophoresis, and also found that TPP does not bond with DNA.

Other compounds will be studied throughout the school year. A compound that interacts with DNA is hoped to be found using similar experiments.