Amine labeling peptides/proteins

Labelling of proteins and peptides with CpRe(CO)3 fragments can be made by peptide bond formation with the carboxylic acid Re(CpCOOH)(CO)3 or by acylation of free amine groups with organometallic succinimidyl esters. 

Imaging/Labeling Applications Amines " neomycin " nucleic acids peptides " proteins - " silane coupling agent " " silica particles/beads " " ... 

Unlike bovine serum amine oxidase, which is available in gram quantities and was used as the prototypic system for the establishment of TPQ, a typical preparation of LO yields about 5 mg (starting with about 500 grams of aorta tissue). In an effort to minimize protein loss, purification was stopped after the stage where LO (32 kDa) coelutes with a second protein (24 kDa) from Sephacryl S-200 gel filtration. The two-banded protein was labeled with [ 4C]phenyl-hydrazine, to yield the expected chromophore for a phenylhydrazone derivative of a quinone structure (Fig. 1). Analysis of the i C-labeled protein by SDS gel electrophoresis showed almost exclusive incoiporation of into the 32-kDa LO band (13). Therefore, the unreactive 24-kDa band would not affect subsequent procedures since selection of active site-derived peptides from LO was dependent on screening for in addition to monitoring die UV-Vis absorption of the newly formed chromophore. 

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