mmSearch

High Mass Accuracy Sensitive Scoring LC-MS/MS Database Search Provides High Confidence and Low FDR for Peptide, Protein, PTM and Crosslink Identification

What is mmSearch

mmSearch is a protein database search software designed to identify peptides, proteins, PTMs and crosslinks from tandem mass spectrometry (MS/MS) data. 

mmSearch uses a mass accuracy sensitive probabilistic scoring model to match tandem mass spectra with theoretical peptide sequences derived from a comprehensive protein database.

Our innovative approach ensures higher sensitivity and specificity in peptide, protein, PTM and crosslink identification, outperforming traditional search algorithms, especially in datasets with high mass accuracy.

mmSearch screen shot pic-9LcDNxu1

Key Advantages of mmSearch

visual of protein molecules

Crosslink / Disulfide Bond Identification Made Easy

Proteins and peptides with disulfide bonds and chemical cross links can be directly identified without chemical reduction and/or other derivatization, like normal proteins and peptides. Our unique X​ Mapper​ algorithm scores disulfide bonds and chemical crosslinks by aggregating peptide matches.

precision lab

PTM Search

MassMatrix provides high sensitivity and specificity for the identification and site localization of post-translational modifications on proteins and peptides.

data analysis charts

Mass Accuracy Sensitive Scoring

Mass accuracy is an important component of mmSearch's scoring algorithm. As mass accuracy improves so does your confidence in peptide spectral matches. Scoring that takes sequence information into effect and uses mass accuracy consistently lowers FDR and allows for a larger search space.

Erlenmeyer flask

Hierarchical MSn(n>=3) Spectral Database Searching

MS2 ↔ MSn>=3 search algorithm raises scores and confidence when searching peptides with significant neutral loss such as phosphopeptides.

The Science Behind mmSearch

Xu, Hua, and Michael A Freitas. “MassMatrix: a database search program for rapid characterization of proteins and peptides from tandem mass spectrometry data.” Proteomics vol. 9,6 (2009): 1548-55. doi:10.1002/pmic.200700322
Xu H, Zhang L, Freitas MA. Identification and characterization of disulfide bonds in proteins and peptides from tandem MS data by use of the MassMatrix MS/MS search engine. J Proteome Res. 2008 Jan;7(1):138-44. doi: 10.1021/pr070363z. Epub 2007 Dec 12. PMID: 18072732; PMCID: PMC2749473.
Gardner ML, Freitas MA. Multiple Imputation Approaches Applied to the Missing Value Problem in Bottom-Up Proteomics. Int J Mol Sci. 2021 Sep 6;22(17):9650. doi: 10.3390/ijms22179650. PMID: 34502557; PMCID: PMC8431783.
Xu H, Wang L, Sallans L, Freitas MA. A hierarchical MS2/MS3 database search algorithm for automated analysis of phosphopeptide tandem mass spectra. Proteomics. 2009 Apr;9(7):1763-70. doi: 10.1002/pmic.200800282. PMID: 19288523; PMCID: PMC2775432.
Xu H, Freitas MA. Monte carlo simulation-based algorithms for analysis of shotgun proteomic data. J Proteome Res. 2008 Jul;7(7):2605-15. doi: 10.1021/pr800002u. Epub 2008 Jun 11. PMID: 18543962; PMCID: PMC2749500.
Xu H, Hsu PH, Zhang L, Tsai MD, Freitas MA. Database search algorithm for identification of intact cross-links in proteins and peptides using tandem mass spectrometry. J Proteome Res. 2010 Jul 2;9(7):3384-93. doi: 10.1021/pr100369y. PMID: 20469931; PMCID: PMC4141472.
Zhang L, Gardner ML, Jayasinghe L, Jordan M, Aldana J, Burns N, Freitas MA, Guo P. Detection of single peptide with only one amino acid modification via electronic fingerprinting using reengineered durable channel of Phi29 DNA packaging motor. Biomaterials. 2021 Sep;276:121022. doi: 10.1016/j.biomaterials.2021.121022. Epub 2021 Jul 10. PMID: 34298441; PMCID: PMC8405592.
Xu, H., Yang, L. & Freitas, M.A. A robust linear regression based algorithm for automated evaluation of peptide identifications from shotgun proteomics by use of reversed-phase liquid chromatography retention time. BMC Bioinformatics 9, 347 (2008). https://doi.org/10.1186/1471-2105-9-347
Zhang L, Xu H, Chen CL, Green-Church KB, Freitas MA, Chen YR. Mass spectrometry profiles superoxide-induced intramolecular disulfide in the FMN-binding subunit of mitochondrial Complex I. J Am Soc Mass Spectrom. 2008 Dec;19(12):1875-86. doi: 10.1016/j.jasms.2008.08.004. Epub 2008 Aug 12. PMID: 18789718; PMCID: PMC2614441.
Xu, H., Freitas, M.A. A mass accuracy sensitive probability based scoring algorithm for database searching of tandem mass spectrometry data. BMC Bioinformatics 8, 133 (2007). https://doi.org/10.1186/1471-2105-8-133
Xu, H., Freitas, M.A. A Dynamic Noise Level Algorithm for Spectral Screening of Peptide MS/MS Spectra. BMC Bioinformatics 11, 436 (2010). https://doi.org/10.1186/1471-2105-11-436
Hua Xu, Michael A. Freitas, Automated diagnosis of LC-MS/MS performance, Bioinformatics, Volume 25, Issue 10, May 2009, Pages 1341–1343, https://doi.org/10.1093/bioinformatics/btp155