Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.27 (thermolysin)
 1,894 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dialkylsilanediols have been found to be an effective functional group for the design of active-site-directed protease inhibitors, including aspartic (HIV protease) and metallo (ACE and thermolysin) proteases. The use of silanediols is predicated on its resemblance to the hydrated carbonyl transition-state structure of amide hydrolysis. This concept has been tested by replacing the presumed tetrahedral carbon of a thermolysin substrate with a silanediol group, resulting in an inhibitor with an inhibition constant K(i) = 40 nM. The structure of the silanediol bound to the active site of thermolysin was found to have a conformation very similar to that of a corresponding phosphonamidate inhibitor (K(i) = 10 nM). In both cases, a single oxygen is within bonding distance to the active-site zinc ion, mimicking the presumed tetrahedral transition state. There are binding differences that appear to be related to the presence or absence of protons on the oxygens attached to the silicon or phosphorus. This is the first crystal structure of an organosilane bound to the active site of a protease.
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PMID:Structural analysis of silanediols as transition-state-analogue inhibitors of the benchmark metalloprotease thermolysin. 1634 43

Efficient and reliable sample delivery has remained one of the bottlenecks for serial crystallography experiments. Compared with other methods, fixed-target sample delivery offers the advantage of significantly reduced sample consumption and shorter data collection times owing to higher hit rates. Here, a new method of on-chip crystallization is reported which allows the efficient and reproducible growth of large numbers of protein crystals directly on micro-patterned silicon chips for in-situ serial crystallography experiments. Crystals are grown by sitting-drop vapor diffusion and previously established crystallization conditions can be directly applied. By reducing the number of crystal-handling steps, the method is particularly well suited for sensitive crystal systems. Excessive mother liquor can be efficiently removed from the crystals by blotting, and no sealing of the fixed-target sample holders is required to prevent the crystals from dehydrating. As a consequence, 'naked' crystals are obtained on the chip, resulting in very low background scattering levels and making the crystals highly accessible for external manipulation such as the application of ligand solutions. Serial diffraction experiments carried out at cryogenic temperatures at a synchrotron and at room temperature at an X-ray free-electron laser yielded high-quality X-ray structures of the human membrane protein aquaporin 2 and two new ligand-bound structures of thermolysin and the human kinase DRAK2. The results highlight the applicability of the method for future high-throughput on-chip screening of pharmaceutical compounds.
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PMID:On-chip crystallization for serial crystallography experiments and on-chip ligand-binding studies. 3131 15