Premium
Exploring the Kinetics and Cleavage Sites of Cysteine Cathepsins for Vaccine Design
Author(s) -
Matson Shayna,
Rivera Kristian,
Becker Tynan,
Kuhn Thomas
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.09854
Subject(s) - chemistry , cathepsin , kinetics , enzyme kinetics , biochemistry , peptide , cleavage (geology) , proteases , cysteine , enzyme , biology , active site , paleontology , physics , quantum mechanics , fracture (geology)
Cysteine proteases are key players in antigen processing, with roles in both pathogen digestion and major histocompatibility complex class II (MHCII) formation. A selection of the cleaved peptide chains are presented to CD4+ T cells to initiate an adaptive immune response. Those peptides that elicit the strongest T cell activation are termed immunodominant. In this project, the kinetics and cleavage preference of cathepsins S and L individually and S, B & H in combination were examined using hemagglutinin (HA) protein from the A/New Caledonia/20/99 H1N1 strain of influenza as a substrate. HA was digested in solution with cathepsins at specific time points both at pH 5.0 and 6.4. Post‐digestion, we separated the products by mass and characterized the peptide fragments using mass spectroscopy. We found that specific core peptides remained intact for up to 16 hours and correspond to a sub‐set of the immunodominant or subdominant HA peptides regardless of how many enzymes were applied. The kinetics of the digestion of cathepsins S, B & H in combination differed by pH with the higher pH showing slower kinetics. Both the individual cathepsins S and L displayed kinetics more similar that of pH 6.4 than 5.0 when the mixture of 3 enzymes were applied. This provides confirmation that the peptide repertoire can be impacted by regulation of the activity of individual cathepsins in addition to the pH of the endosomes where processing occurs. Information on the cleavage sites and kinetics of cathepsins increases in‐silico predictive capacity when designing vaccines against novel pathogens. Support or Funding Information Research funded by NIH grant R01AI118888‐01A1 and NIH grants UL1GM118991, TL4GM118992, or RL5GM118990.