Peptide Sequencing Directly from Solid Surfaces using MALDI Approaches
With the development of high throughput peptide synthesis, particularly on solid surfaces, the number of peptides that can be synthesized can easily reach in the millions. Because there are so many applications in which peptides are synthesized and used directly on solid surface, there is also a need for high throughput in situ sequence analysis directly on solid surfaces. However, common sequencing approaches adapted to be used with surface bound peptides lack the throughput needed for library-based applications.
Researchers at Arizona State University have developed a simple approach for sequence analysis directly on solid surfaces that is both high speed and high throughput, and utilizes commonly available instrumentation. Utilizing this approach, surface bound peptides are selectively labeled at their N-termini with a positive charge-bearing group and, subjected to controlled degradation in ammonia gas. This results in a set of charged peptide fragments differing by a single amino acid that remain spatially confined on the surface they were bound to, which can then be analyzed by MALDI mass spectrometry.
This approach enables robust peptide sequence analysis directly on a solid surface in a position dependent fashion. It does this so quickly and in such a high throughput manner that it may be the fastest, simplest approach to peptide sequencing yet.
• Drug discovery/identifying lead candidates – rapidly sequences peptides on many individual beads in a bead library
• Measuring antibody profiles used in disease diagnosis
• Tool for peptide array or bead library development - enables direct evaluation of the peptides on the surface for modifications
• QC for peptide arrays or bead libraries – sequences multiple peptides directly from arrays or beads
Benefits and Advantages
• High speed & high throughput analyses
• Time-efficient and environmentally-friendly process
• Utilizes widely available equipment such as a desktop mass spectrometer
• Doesn’t require technicians with highly trained analytical skills
• Works well with high peptide numbers
• Well-suited for multiplex analysis of peptide sequences in microarray formats
• Can be used on solid surfaces, in situ without requiring the peptides to be released
• Can evaluate the extent of side reactions during array synthesis and processing
• Hundreds of individual beads can be physically immobilized and treated in one experiment