| Autor: |
Chugunov AO; M.M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.; L.D. Landau School of Physics, Moscow Institute of Physics and Technology (State University), 141701 Dolgoprudny, Russia., Dvoryakova EA; A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia., Dyuzheva MA; M.M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.; Higher Chemical College of the Russian Academy of Sciences, D. Mendeleev University of Chemical Technology, 125047 Moscow, Russia., Simonyan TR; Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia., Tereshchenkova VF; Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia., Filippova IY; Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia., Efremov RG; M.M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia.; L.D. Landau School of Physics, Moscow Institute of Physics and Technology (State University), 141701 Dolgoprudny, Russia.; Department of Applied Mathematics, National Research University Higher School of Economics, 101000 Moscow, Russia., Elpidina EN; A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia. |
| Abstrakt: |
Roughly 1% of the global population is susceptible to celiac disease (CD)-inheritable autoimmune inflammation of the small intestine caused by intolerance to gliadin proteins present in wheat, rye, and barley grains, and called gluten in wheat. Classical treatment is a life-long gluten-free diet, which is constraining and costly. An alternative approach is based upon the development and oral reception of effective peptidases that degrade in the stomach immunogenic proline- and glutamine-rich gliadin peptides, which are the cause of the severe reaction in the intestine. In previous research, we have established that the major digestive peptidase of an insect Tribolium castaneum -cathepsin L-hydrolyzes immunogenic prolamins after Gln residues but is unstable in the extremely acidic environment (pH 2-4) of the human stomach and cannot be used as a digestive aid. In this work, using molecular dynamics simulations, we discover the probable cause of the pH instability of cathepsin L-loss of the catalytically competent rotameric state of one of the active site residues, His 275. To "fix" the correct orientation of this residue, we designed a V277A mutant variant, which extends the range of stability of the peptidase in the acidic environment while retaining most of its activity. We suggest this protein as a lead glutenase for the development of oral medical preparation that fights CD and gluten intolerance in susceptible people. |
