The preparation of rat heme oxygenase-1 mutant to reduce the level of bilirubin

Keywords: heme oxygenase; mutant; hyperbilirubinemia制备大鼠血红素加氧酶-1变异体以降低血清胆红素水平夏振炜邵洁李云珠陈舜年俞善昌申庆祥王健
From: Chinese Medical Journal 2001;114(4):347-351
CountryChina
Language:Chinese
Abstract: Objective To prepare rat heme oxygenase-1 (HO-1) mutants and todetermine the activity and inhibition of this mutated enzyme. Methods pcDNA3HO1 containing truncated native rat HO-1 cDNA and pcDNA3HO1Δ25 carrying mutated rat HO-1 cDNA (His25Ala) were constructed, respectively. COS-1 cells transfected with pcDNA3HO1 and pcDNA3HO1Δ25 were collected and their activities were analyzed. Results Native rat HO-1 was highly expressed in transfected cells and its activity was 13?688-15?600 U/mg protein per hour. However, the enzyme activity of mutated HO-1 declined and the value was 1948-2160 U/mg protein per hour. When an equal amount of mutant was added to the enzyme reaction system, the level of bilirubin decreased by 42%. Conclusion The His25Ala mutant reduced the formation of bilirubin, suggesting that the mutant could competely bind the heme with native enzyme.