Studies of the structure of fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase
| Autor: | Helmut Thomas, E. Glen Richards, Kosaku Uyeda, Ryuzo Sakakibara, Tatsuya Tanaka, Kenji Kangawa, Hisayuki Matsuo |
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| Rok vydání: | 1985 |
| Předmět: |
Phosphopeptides
Arginine Phosphofructokinase-2 Fructose 1 6-bisphosphatase Peptide Biochemistry Multienzyme Complexes Thermolysin Trypsin Phosphofructokinase 2 Amino Acids Peptide sequence Chromatography High Pressure Liquid chemistry.chemical_classification biology Phosphotransferases Carboxypeptidase Peptide Fragments Phosphoric Monoester Hydrolases Molecular Weight Kinetics Isoelectric point chemistry biology.protein Electrophoresis Polyacrylamide Gel |
| Zdroj: | Biochemistry. 24:6818-6824 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi00345a013 |
| Popis: | Some physicochemical properties of a homogeneous preparation of a bifunctional enzyme, fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase, were determined. The molecular weight of the enzyme is 101 000 as determined by high-speed sedimentation equilibrium. The molecular weight of dissociated enzyme is 55 000 in 6 M guanidinium chloride by sedimentation equilibrium and in sodium dodecyl sulfate by polyacrylamide gel electrophoresis. A value of 4.7 was observed for the isoelectric point. Tryptic peptide maps and high-performance liquid chromatography of the trypsin-digested enzyme revealed approximately 60 peptides. Amino acid analysis of the enzyme shows that it contains 27 lysine and 36 arginine residues per 55 000 daltons. No free N-terminal amino acid residue was detectable, suggesting that it is blocked. Hydrolysis of the enzyme by carboxypeptidases A and B releases tyrosine followed by histidine and arginine, indicating that the amino acid sequence at the carboxyl terminus is probably -Arg-His-Tyr. Tryptic digestion of [32P]phosphofructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase yields a 32P-labeled peptide detected by tryptic peptide mapping and high-performance liquid chromatography. Thermolysin digestion of CNBr-cleaved 32P-enzyme also yields a single 32P-peptide. These results indicate that fructose-6-phosphate 2-kinase:fructose-2,6-bisphosphatase is a dimer of 55 000 daltons and the subunits are very similar, if not identical. |
| Databáze: | OpenAIRE |
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