By Veena Venkatachalam

• Neurons – cells that make up our nervous systems

• have processes that transmit electrical impulses (action potentials)

• this is how your brain communicates with the rest of your body

• neurodegenerative diseases cause these neurons to die

• basic fibroblast growth factor (bFGF) promotes neuron survival

• bFGF – growth factor that stimulates elongation and branching of neuronal processes

• Why don’t we use bFGF to treat patients with Alzheimer’s or Parkinson’s disease? It degrades too rapidly!

• Solution – find a stable substance that has bFGF-like effects

• Antibodies – Y-shaped proteins that are produced by cells of the immune system in response to a stimulus; protect us by neutralizing toxins

• four chains – two heavy chains and two light chains

• each chain has one variable region; variable regions differentiate antibodies from one other and determine specificity

• We have hypothesized, based on past observations, that serum from several patients contains an antibody that has effects similar to those of bFGF

bFGF (neurotrophic growth factor)

Complementary

Anti-idiotype (bFGF-like

antibody; similar antigen binding

site)

Idiotype (antibody complementary to

bFGF)

Complementary

• We used three different methods to purify the patient serum:

Protein A beads: pour serum over column and elute with citric acid; result => only

IgGs

Protein A

beads: bind IgGs

Hydroxy-apatite

gel

Hydroxyapatite (HA) column: pour protein A

eluate over column, elute w/ diff. molarities of sodium phosphate

Immunoaffinity column: has anti-bFGF antibodies bound to

the protein A beads; thus, bFGF like antibodies bind very

strongly. Elute w/ diff. pH

Immuno-affinity column

• Bioactivity assays were used to determine the fraction that we wanted to purify further

pH fractions from IA column: bioassay

100.00%

110.00%

120.00%

130.00%

140.00%

150.00%

160.00%

Control pH 3.3 pH 3.0 pH 2.8 pH 2.65 pH 2.3

pe

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con

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0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

pro

tein

co

nce

ntr

atio

n (

mg

/mL

)

bioactivity (endothelial cell assay) protein conc

I’d like to extend my deepest appreciation to Dr. Zimering for his guidance. I would also like to thank Robert Donnelly for his help in running

mass spectroscopy and amino acid sequencing our samples.