Hovik R, Osmundsen H
Department of Physiology and Biochemistry, Dental School, University of Oslo, Norway.
Biochem J. 1987 Nov 1;247(3):531-5. doi: 10.1042/bj2470531.
Rates of peroxisomal beta-oxidation were measured as fatty acyl-CoA-dependent NAD+ reduction, by using solubilized peroxisomal fractions isolated from livers of rats treated with clofibrate. Medium- to long-chain saturated fatty acyl-CoA esters as well as long-chain polyunsaturated fatty acyl-CoA esters were used. Peroxisomal beta-oxidation shows optimal specificity towards long-chain polyunsaturated acyl-CoA esters. Eicosa-8,11,14-trienoyl-CoA, eicosa-11,14,17-trienoyl-CoA and docosa-7,10,13,16-tetraenoyl-CoA all gave Vmax. values of about 150% of that obtained with palmitoyl-CoA. The Km values obtained with these fatty acyl-CoA esters were 17 +/- 6, 13 +/- 4 and 22 +/- 3 microM respectively, which are in the same range as the value for palmitoyl-CoA (13.8 +/- 1 microM). Myristoyl-CoA gave the higher Vmax. (110% of the palmitoyl-CoA value) of the saturated fatty acyl-CoAs tested. Substrate inhibition was mostly observed with acyl-CoA esters giving Vmax. values higher than 50% of that given by palmitoyl-CoA.
通过使用从用氯贝丁酯处理的大鼠肝脏中分离出的可溶性过氧化物酶体组分，以脂肪酰基辅酶A依赖的NAD⁺还原反应来测定过氧化物酶体β-氧化速率。使用中链至长链饱和脂肪酰基辅酶A酯以及长链多不饱和脂肪酰基辅酶A酯。过氧化物酶体β-氧化对长链多不饱和脂肪酰基辅酶A酯表现出最佳特异性。二十碳-8,11,14-三烯酰辅酶A、二十碳-11,14,17-三烯酰辅酶A和二十二碳-7,10,13,16-四烯酰辅酶A的Vmax值均约为棕榈酰辅酶A的150%。用这些脂肪酰基辅酶A酯获得的Km值分别为17±6、13±4和22±3微摩尔，与棕榈酰辅酶A的值（13.8±1微摩尔）处于同一范围。肉豆蔻酰辅酶A在所测试的饱和脂肪酰基辅酶A中具有较高的Vmax（为棕榈酰辅酶A值的110%）。底物抑制主要在Vmax值高于棕榈酰辅酶A的50%的酰基辅酶A酯中观察到。
