The study on phosphatidylinositol-specific phospholipase C from Bacillus thuringiensis: synthesis of homogeneous substrates, substrate specificity and other properties
| Autor: | Hiroh Ikezawa, Jiro Hirano, Takashi Kume, Nakachi Osamu, Ryo Taguchi, Satoru Tokuyama, Masahiro Tomita, Kazuya Morizawa |
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| Rok vydání: | 1992 |
| Předmět: |
chemistry.chemical_classification
Phospholipase C biology Chemistry Stereochemistry Bacillus thuringiensis General Chemistry General Medicine Phosphatidylinositols Yeast Dithiothreitol Substrate Specificity chemistry.chemical_compound Hydrolysis Enzyme Biochemistry Deoxyadenosine Bacterial Proteins Type C Phospholipases Drug Discovery biology.protein Phosphatidylinositol Bovine serum albumin |
| Zdroj: | Chemicalpharmaceutical bulletin. 40(8) |
| ISSN: | 0009-2363 |
| Popis: | The properties of phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis were studied in detail. The enzyme was extremely thermostable in 0.1% bovine serum albumin and retained 73% of its activity at 100 degrees C for 10 min, while it was labile in the absence of albumin. The enzymatic activity was inhibited by HgCl2 or p-chloromercuriphenylsulfonic acid and restored by dithiothreitol. The kinetic parameters (Km and Vmax) of PI-PLC were determined for the mixed micelle of yeast phosphatidylinositol (PI)/Triton X-100 or sodium deoxycholate. Four PIs having different acyl chains: dilauroylphosphatidylinositol (DLPI), dimyristoylphosphatidylinositol (DMPI), dipalmitoylphosphatidylinositol (DPPI) and dioleoylphosphatidylinositol (DOPI) were synthesized from yeast PI through the processes of deacylation and reacylation, identified by infrared (IR) and Fourier transform nuclear magnetic resonance (FT-NMR) spectra, and subjected to the action of PI-PLC. All the synthetic PIs were hydrolyzed by this enzyme, with DLPI and DMPI being the best substrates. PI-PLC did not catalyze the hydrolysis of the phosphatidylnucleosides 5'-phosphatidylcytidine, 5'-phosphatidyluridine, 5'-phosphatidylthymidine, 5'-phosphatidyladenosine and 5'-phosphatidyl-2'-deoxyadenosine. |
| Databáze: | OpenAIRE |
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