BIOC 2580 Lecture Notes - Lecture 3: Silica Gel, Protein Structure, Ninhydrin
26 Feb 2018
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Partition chromatography is an important method for separating. Components of a mixture: particles of solid are chosen with a specific property, e. g. silica gel has. Elution: when a protein emerges from a column. As [na+] is increased, more tightly bound amino acids are progressively displaces: alternatively, ph may be increased to eliminate the positive charge on the amino acid so it no longer binds to the resin. Charge differences among peptides and proteins: at ph 7, ala-asp-leu-gly-his-gln-tyr-cys-iie-glu-lys-ser-thr. +1 -due to n- and c- terminal - -1. Net charge = +1 -1 + 0. 24 -1 +1 -1 = -0. 76: peptides and proteins can show large differences in charge, ion exchange is frequently used to separate protein mixtures. Homework questions: calculate the overall net charge of the following polypeptide at ph=12. 8. Iie-gln-his-arg-trp-asp: which of the following peptides (represented by their one-letter codes) would bind most tightly to a cation-exchange column, at neutral ph, camilla, edward, harry, philip, william.
