| 摘要 |
PURPOSE:To produce a II type restriction enzyme having improved enzymological properties such as stability to dilution, stable range in salt concentration, thermostability, etc., by cultivating a bacterium belonging to the genus Gluconobacter, capable of producing GceinI, II type restriction enzyme. CONSTITUTION:A bacterium (e.g. Gluconobacter cerius IFO 3260) belonging to the genus Gluconobacter, capable of producing GceinI, II type restriction enzyme, is inoculated into a medium containing a carbon source, a enzyme, is inoculated into a medium containing a carbon source, a nitrogen source, an inorganic salt and a natural organic nutrient and aerobically cultivated at pH5-7 at 25-30 deg.C for 24-48hr. Then the culture solution is centrifuged to give a bacterial cell, which is washed with a buffer solution the cell is ground, centrifuged and the precipitate is removed to give a cell-free extracted solution. Then the extracted solution is treated with streptomycin sulfate, fractioned with (NH4)2SO4 and purified to give GceinI, II type restriction enzyme, which recognizes the base sequence shown by the formula (A is adenosine; G is guanosine; T is thymidine; C is cytidine) in the molecule of duplex deoxyribonucleic acid and cleaves the sequence at the position shown by the arrow. |
