Hemler M E, Lands W E
Lipids. 1977 Jul;12(7):591-5. doi: 10.1007/BF02533387.
Highly purified cyclooxygenase from sheep vesicular glands is stimulated by the presence of protoporphyrin IX compounds. This stimulation may be due to the conversion of an apoenzyme to the holoenzyme, and full activity is achieved when half of the enzyme subunits (70,000 daltons) bind heme. Also, one-half of the subunits appear to contain non-heme iron. The apparent molecular weight of the holoenzyme is approximately 300,000 daltons and is compatible with a complex of four 70,000 dalton subunits. Thus, we suggest that heme and non-heme iron may be attached to different 70,000 daltons subunits that make up an A2B2-type of peptide chain arrangement.
来自绵羊精囊的高度纯化的环氧化酶受到原卟啉IX化合物的刺激。这种刺激可能是由于脱辅基酶转变为全酶，当一半的酶亚基（70,000道尔顿）结合血红素时可达到完全活性。此外，一半的亚基似乎含有非血红素铁。全酶的表观分子量约为300,000道尔顿，与四个70,000道尔顿亚基组成的复合物相符。因此，我们认为血红素和非血红素铁可能附着于构成A2B2型肽链排列的不同70,000道尔顿亚基上。
