5. Separation of Amino Acids by Ion-Exchange Chromatography Mixtures of amino acids can be analyzed by first
separating the mixture into its components through ionexchange chromatography. Amino acids placed on a cationexchange resin (see Fig. 3–17a) containing sulfonate (OSO2
3 )
groups flow down the column at different rates because of two
factors that influence their movement: (1) ionic attraction
between the sulfonate residues on the column and positively
charged functional groups on the amino acids, and (2) hydrophobic interactions between amino acid side chains and the
strongly hydrophobic backbone of the polystyrene resin. For
each pair of amino acids listed, determine which will be eluted
first from the cation-exchange column by a pH 7.0 buffer.
(a) Asp and Lys
(b) Arg and Met
(c) Glu and Val
(d) Gly and Leu
(e) Ser and Ala![]()
[answer.2.content]
separating the mixture into its components through ionexchange chromatography. Amino acids placed on a cationexchange resin (see Fig. 3–17a) containing sulfonate (OSO2
3 )
groups flow down the column at different rates because of two
factors that influence their movement: (1) ionic attraction
between the sulfonate residues on the column and positively
charged functional groups on the amino acids, and (2) hydrophobic interactions between amino acid side chains and the
strongly hydrophobic backbone of the polystyrene resin. For
each pair of amino acids listed, determine which will be eluted
first from the cation-exchange column by a pH 7.0 buffer.
(a) Asp and Lys
(b) Arg and Met
(c) Glu and Val
(d) Gly and Leu
(e) Ser and Ala
