To biotinylate a small peptide, there are two relatively simple methods. The first, as you
suggested, is to derivitise the peptide with a c-terminus cysteine and use a maleimide activated,
an iodoacetylbiotin, or a pyridoldi thio biotin. The other popular method is to use the n-terminus
and/or lysine groups and conjugate with an NHS ester derivitised biotin. These are nice because
they are available sulfonated to make them water soluble. The real problem is going to be
removal of the biotinylation reagent after conjugation. Most of these reagents are around 500
daltons so seperation is possible through desalting columns or dialysis, but HPLC may be
required.
Tom Brotcke
Technical Assistance
Pierce Chemical Co
Phone: 1-815-968-0747
Fax: 1-815-968-7316
E-mail: PierceChem at mcimail.com
