TERM 1
Ion exchange chromatography (IEX)
DEFINITION 1
separates proteins based on charge. THe amino acids of
proteins electrostatically bind to a column containing the
opposite charge and it elutes it by changing the salt
concentration or pH
TERM 2
isoelectric point (pI)
DEFINITION 2
the pH at which there is an overall n et neutral charge on the
moleculte. The positive or negative c harge cancel eachother out.
the net charge of a protein is depend ent upon the pH of the
surrounding buffer. if the pH increase s above the pI, then protons
dissociate from proteins side chains an d leave a negative charge
on molecule. If pH decreases below t he pI, protons associate with
the protein and give it a positive char ge.
TERM 3
anion exchanger
DEFINITION 3
one of 2 types of ion exchangers which chemically bind
negative charges. These charges on the exchangers are
balanced by counterions. for Anion the counterion is chloride
TERM 4
cation exchanger
DEFINITION 4
an ion exchanger that binds to positive charges and the ion
exchanger is an metal ion for cation. ion exchangers are
named for the counterion
TERM 5
anion exchange chromatography
DEFINITION 5
exchanges negatively charged anions which is done by using
beads with a positive charge. The pH of the buffer must be
high than the pI of the protein
