| Autor: |
Saratov GA; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.; Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), 141701 Dolgoprudny, Russia., Vladimirov VI; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia., Novoselov AL; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia., Ziganshin RH; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia., Chen G; School of Biopharmacy, China Pharmaceutical University, Nanjing 211198, China., Baymukhametov TN; National Research Center, 'Kurchatov Institute', 123182 Moscow, Russia., Konevega AL; National Research Center, 'Kurchatov Institute', 123182 Moscow, Russia.; Institute of Biomedical Systems and Biotechnologies, Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia.; Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre, Kurchatov Institute, 188300 Gatchina, Russia., Belogurov AA Jr; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.; Department of Biological Chemistry, Ministry of Health of Russian Federation, Evdokimov Moscow State University of Medicine and Dentistry, 127473 Moscow, Russia., Kudriaeva AA; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia. |
| Abstrakt: |
Proteasomes exist in mammalian cells in multiple combinatorial variants due to the diverse regulatory particles and exchange of catalytic subunits. Here, using biotin carboxyl carrier domain of transcarboxylase from Propionibacterium shermanii fused with different proteasome subunits of catalytic and regulatory particles, we report comprehensive characterization of highly homogenous one-step purified human constitutive and immune 20S and 26S/30S proteasomes. Hydrolysis of a multiple sclerosis (MS) autoantigen, myelin basic protein (MBP), by engineered human proteasomes with different catalytic phenotypes, revealed that peptides which may be directly loaded on the HLA class I molecules are produced mainly by immunoproteasomes. We detected at least five MBP immunodominant core regions, namely, LPRHRDTGIL, SLPQKSHGR, QDENPVVHFF, KGRGLSLSRF and GYGGRASDY. All peptides, except QDENPVVHFF, which originates from the encephalitogenic MBP part, were associated with HLA I alleles considered to increase MS risk. Prediction of the affinity of HLA class I to this peptide demonstrated that MS-protective HLA-A*44 and -B*35 molecules are high-affinity binders, whereas MS-associated HLA-A*23, -A*24, -A*26 and -B*51 molecules tend to have moderate to low affinity. The HLA-A*44 molecules may bind QDENPVVHFF and its deamidated form in several registers with unprecedently high affinity, probably linking its distinct protective phenotype with thymic depletion of the repertoire of autoreactive cytotoxic T cells or induction of CD8+ regulatory T cells, specific to the encephalitogenic MBP peptide. |
