The PAN Biotechnology Facility offers several services for identifying proteins and for determining primary sequence information for proteins and peptides.

De Novo N-terminal Sequencing: The PAN Facility also offers automated sequencing of proteins and peptides. Sequencing is performed by Edman chemistry, a process whereby amino acids are sequentially cleaved and identified starting at the protein’s amino terminus.

Internal Sequencing of peptides generated by enzymatic digestion is offered as well. This is often employed for generating "de novo" primary sequence used in cloning projects.  Thus, this method is useful for the characterization of proteins from organisms whose genomes are not fully sequenced.  For such samples, we will digest the protein, isolate the resulting peptide fragments by HPLC, and sequence the peptides by automated Edman analysis.  We typically digest proteins with trypsin; we can also employ alternative enzymes with differing cleavage specificities.

Mass Mapping is a convenient method for determining the identity of proteins. Mass mapping involves tryptic digestion of proteins and mass analysis of the resulting mixture of peptides.  As long as a protein’s sequence is present in a database, it can be accurately identified by this method.

Protein Sequencing/Mass Mapping
PAN is able to provide primary sequence information by Edman analysis from proteins free in solution or immobilized on PVDF membranes. These procedures extend to protease digestion, separation by HPLC and subsequent Edman sequencing of peptides.  For those organisms whose genomes are sequenced, mass mapping can identify proteins at subpicomole levels.