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以嗜热脂肪芽孢杆菌（Ｂａｃｉｌｕｓｓｔｅａｒｏｔｈｅｒｍｏｐｈｉｌｕｓ）为材料，通过ＰｏｌｙｍｉｎＰ沉淀、硫酸铵分级及ＤＥＡＥ纤维素、磷酸纤维素、Ｂｌｕｅ－Ｓｅｐｈａｒｏｓｅ、ＦＰＬＣＭｏｎｏＱ、ＦＰＬＣＳｕｐｅｒｏｓｅ１２等柱层析，得到了部分纯化的ＤＮＡ解链蛋白ＢｓｔＨ２。ＢｓｔＨ２具有受ＤＮＡ促进的ＡＴＰ酶活力，不同类型的核酸对ＢｓｔＨ２的ＡＴＰ酶活力的促进作用不同。ＢｓｔＨ２在５５°Ｃ有最高ＡＴＰ酶活力。这种活力受大肠杆菌单链ＤＮＡ结合蛋白的抑制及随离子强度的增强而下降。ＢｓｔＨ２具有ＤＮＡ解链活力，不但能解开部分双链ＤＮＡ，也能解开钝末端的双链ＤＮＡ，解链反应需要ＡＴＰ和Ｍｇ２＋。大肠杆菌单链ＤＮＡ结合蛋白促进ＤＮＡ解链反应。
Using Bacillus stearothermophilus as material, the partially purified DNA unbound protein BstH2 was obtained by column chromatography with PolyminP precipitation, ammonium sulfate fractionation and DEAE cellulose, phosphocellulose, Blue-Sepharose, FPLCMonoQ and FPLC Superose12. . BstH2 has DNA-promoted ATPase activity, and different types of nucleic acids have different promoting effects on BstH2’s ATPase activity. BstH2 has the highest ATPase activity at 55 ° C. This activity is inhibited by E. coli single-stranded DNA binding protein and decreases with increasing ionic strength. BstH2 has DNA melting activity, which can not only cleave some double-stranded DNA, but also cleave the blunt-ended double-stranded DNA. The melting reaction requires ATP and Mg2 +. Escherichia coli single-stranded DNA binding protein promotes DNA unwinding reaction.