8HWU
Solution structure of frog peptide LL-TIL
Summary for 8HWU
| Entry DOI | 10.2210/pdb8hwu/pdb |
| Descriptor | LL-TIL (1 entity in total) |
| Functional Keywords | inhibitor, hydrolase |
| Biological source | Lepidobatrachus laevis |
| Total number of polymer chains | 1 |
| Total formula weight | 6354.56 |
| Authors | Rami, M.J.,Sarma, S.P. (deposition date: 2023-01-03, release date: 2023-11-15, Last modification date: 2024-10-16) |
| Primary citation | Rami, M.,Shafique, M.,Sarma, S.P. Structural, Functional, and Mutational Studies of a Potent Subtilisin Inhibitor from Budgett's Frog, Lepidobatrachus laevis. Biochemistry, 62:2952-2969, 2023 Cited by PubMed Abstract: Subtilases play a significant role in microbial pathogen infections by degrading the host proteins. Subtilisin inhibitors are crucial in fighting against these harmful microorganisms. LL-TIL, from skin secretions of , is a cysteine-rich peptide belonging to the I8 family of inhibitors. Protease inhibitory assays demonstrated that LL-TIL acts as a slow-tight binding inhibitor of subtilisin Carlsberg and proteinase K with inhibition constants of 91 pM and 2.4 nM, respectively. The solution structures of LL-TIL and a mutant peptide reveal that they adopt a typical TIL-type fold with a canonical conformation of a reactive site loop (RSL). The structure of the LL-TIL-subtilisin complex and molecular dynamics (MD) simulations provided an in-depth view of the structural basis of inhibition. NMR relaxation data and molecular dynamics simulations indicated a rigid conformation of RSL, which does not alter significantly upon subtilisin binding. The energy calculation for subtilisin inhibition predicted Ile as the highest contributor to the binding energy, which was confirmed experimentally by site-directed mutagenesis. A chimeric mutant of LL-TIL broadened the inhibitory profile and attenuated subtilisin inhibition by 2 orders of magnitude. These results provide a template to engineer more specific and potent TIL-type subtilisin inhibitors. PubMed: 37796763DOI: 10.1021/acs.biochem.3c00252 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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