| 摘要 |
PURPOSE:To obtain the subject enzyme, composed of a hybrid ribonuclease H having cysteine residue in which thiol group is linked to oligodeoxyribonucleotide through covalent bond without affecting enzymic activity and having high selectivity and catalytic activity. CONSTITUTION:A gene capable of coding Escherichia coli ribonuclease H is converted into a gene capable of coding variant type ribonuclease H in which amino acid at the 131-, 135-, 138or 142-position located on the molecular surface is substituted with cysteine by enzymic treatment, subjected to treatment with a restriction enzyme, linked to a vector, transduced into Escherichia coli and expressed to prepare a variant type ribonuclease H. The resultant variant type ribonuclease H is subsequently reacted with a compound, expressed by formula II and prepared by reacting an oligodeoxyribonucleotide having amino group expressed by formula I introduced thereinto with N-(epsilon-maleimidocaproyloxy) succinimide to afford the objective hybrid ribonuclease H in which the variant type ribonuclease having the cysteine residue on the molecular surface is linked to the oligodeoxyribonucleotide without affecting the enzymic activity. |
