Related Experiment Video
Updated: Jul 12, 2026
Peptide and Protein Quantification Using Automated Immuno-MALDI iMALDI
Published on: August 18, 2017
Identification of substrates of MBL Associated Serine Protease-1 (MASP-1) from human plasma using N-terminomics
Sonali R Bhagwat1, Komal Choudhary2, Nirali Pandya3
1Discipline of Biosciences and Biomedical Engineering, IIT, Indore, India; School of Life Sciences, DAVV, Indore, India.
Abstract:
MBL Associated Serine Protease-1 (MASP-1) is an abundant enzyme of the lectin complement pathway. MASP-1 cleaves numerous substrates like MASP-2, MASP-3, C2, C3i, fibrinogen, FXIII and prothrombin. It has thrombin-like specificity and can cleave thrombin substrates. Owing to its high concentration and relaxed substrate specificity, MASP-1 has substrates outside the complement system and can influence other proteolytic cascades and physiological processes. The unidentified substrates may assist us to ascertain the role(s) of MASP-1. In this study, we used a high-throughput N-terminomics method to identify substrates of MASP-1 from human plasma. We have identified 35 putative substrates of MASP-1. Among the identified proteins, alpha 2-antiplasmin, alpha-1-acid glycoprotein, antithrombin III, and siglec-6 were demonstrated to be cleaved by MASP-1. We have discussed the physiological relevance of cleavage of these substrates by MASP-1. The expression of Siglec-6 and MASP-1 has been reported in the B cells. Alpha-1-acid glycoprotein cleavage by MASP-1 may occur in the acute phase as it is known to be an inhibitor of platelet aggregation, whereas MASP-1 triggers platelet aggregation. The cleavage alpha2 antiplasmin by MASP-1 implies that MASP-1 may be promoting plasmin-mediated fibrinolysis. Our study supports that MASP-1 may be implicated in thrombosis as well as thrombolysis.
Insights
MBL Associated Serine Protease-1 (MASP-1) cleaves numerous proteins beyond the complement system. This study identified 35 new substrates, revealing MASP-1
Area of Science:
- Biochemistry
- Immunology
- Proteomics
Background:
- MBL Associated Serine Protease-1 (MASP-1) is a key enzyme in the lectin complement pathway.
- MASP-1 exhibits broad substrate specificity, cleaving molecules within and outside the complement system.
- Understanding MASP-1's substrates is crucial for elucidating its diverse physiological roles.
Purpose of the Study:
- To identify novel substrates of MASP-1 in human plasma.
- To investigate the physiological relevance of MASP-1-mediated cleavage of specific proteins.
Main Methods:
- Employed a high-throughput N-terminomics approach.
- Analyzed human plasma samples to identify MASP-1 cleavage products.
Main Results:
- Identified 35 putative substrates of MASP-1.
- Confirmed cleavage of alpha 2-antiplasmin, alpha-1-acid glycoprotein, antithrombin III, and siglec-6 by MASP-1.
- Discussed the implications of these cleavages in platelet aggregation, acute phase response, and fibrinolysis.
Conclusions:
- MASP-1 possesses a wider range of substrates than previously known, influencing multiple biological processes.
- MASP-1's cleavage of identified proteins suggests roles in thrombosis and thrombolysis.
- Further research into MASP-1 substrates can uncover its involvement in various physiological and pathological conditions.
Related Concept Videos
01:33Peptide Identification Using Tandem Mass Spectrometry
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
01:25Rapid Identification of Pathogens