Morpheus

Morpheus identifies peptides and proteins from high-resolution tandem mass spectra (MS/MS) for proteomic analysis.

Key Features:

• High-resolution MS/MS support: Optimized for analysis of high-mass-accuracy tandem mass spectra (MS/MS).
• Scoring mechanism: Employs a straightforward scoring approach based primarily on counting matching product ions between experimental and theoretical spectra.
• Performance: Achieves higher numbers of spectrum, peptide, and protein identifications at a 1% false discovery rate (FDR) compared with Mascot, Open Mass Spectrometry Search Algorithm (OMSSA), and Sequest.
• Speed: Processes datasets 1.5 to 4.6 times faster than OMSSA depending on the dataset.
• Validation datasets: Evaluated on MS/MS data from E. coli, yeast, and human collected on quadrupole-time-of-flight (Q-TOF), ion trap-orbitrap, and quadrupole-orbitrap instruments across multiple laboratories.
• Algorithmic focus: Designed to address limitations of traditional peptide identification algorithms that were not optimized for high-mass-accuracy data.
• Implementation: Implemented in C# .NET.

Scientific Applications:

• Peptide and protein identification: Identification of peptides and proteins from high-resolution MS/MS spectra for proteomic studies.
• Benchmarking: Comparative evaluation of search algorithm sensitivity and specificity across algorithms such as Mascot, OMSSA, and Sequest at fixed FDR thresholds.
• Cross-platform proteomics: Analysis of proteomic datasets acquired from diverse organisms and instruments, including Q-TOF, ion trap-orbitrap, and quadrupole-orbitrap systems.

Methodology:

Search scoring is performed by counting matching product ions between experimental and theoretical spectra; the algorithm is implemented in C# .NET.