New N- and C-terminal Protein Sequencing Service

Alphalyse now offers N- and C-terminal sequencing of purified proteins using In-source-decay (ISD) MALDI mass spectrometry.

March 2009

Analytical characterization of purified proteins includes confirmation of full length protein sequence as quality control of correct protein expression and purification. N- and C-terminal sequencing is included in the ICH Q6B Guidelines; Test procedures and acceptance criteria for biotechnological/biological products.

N- and C-terminal sequencing is offered as part of Alphalyse’s protein analytical services which are designed to assist pharma, biotech, academic and CMO customers in the purification and development of natural and recombinant protein products. The sequencing is conducted by In-Source-Decay MALDI Mass Spectrometry (ISD MALDI MS), a technique that provides mass spectrometric sequencing of peptides and intact proteins.

The  application note “N- and C-terminal sequencing by MALDI ISD #200902”, by Mortz E., Thanh HN, and Crawford J demonstrates that the technique can be applied to a variety of natural and recombinant proteins and monoclonal antibodies. The analysis typically provides sequence confirmation of 20-50 residues from both the N-terminal and the C-terminal of the intact protein in a single ISD MALDI mass spectrum. This sequencing technique has several advantages over traditional N-terminal Edman sequencing:

• The sequencing covers both protein termini and provides both the C-terminal and N-terminal sequence.
• N-terminal blocked proteins can be sequenced.
• The sequence reads are long providing 20-50 residues from both termini in just one single ISD MALDI spectrum.

“MALDI ISD is a unique method that provides both the C-terminal as well as N-terminal sequence assignment in one go “, says Ejvind Mørtz, COO of Alphalyse A/S. “We are very happy that the analysis has been so well received by our customers in support of their recombinant protein development”.

For more information, please contact
Europe:  Ejvind Mørtz, COO, Alphalyse A/S +4563106500 or email mortz@alphalyse.com
USA/Canada: Andrew Munk, COO, Alphalyse Inc. (650) 534-3193 or email munk@alphalyse.com