Suzuki T, Kovacs M S, Board P G
Molecular Genetics Group, John Curtin School of Medical Research, Australian National University, Canberra, A.C.T.
FEBS Lett. 1990 Nov 26;275(1-2):58-60. doi: 10.1016/0014-5793(90)81438-t.
Two fatty acid ethyl ester (FAEE) synthase isoenzymes purified from human myocardium were reported to be glutathione S-transferases (GST) [(1989) Proc. Natl. Acad. Sci. USA 86, 4470-4473; and (1989) J. Clin. Invest. 84, 1942-1946]. In the present study, the FAEE synthase activity of several purified and well characterized human GSTs were examined with ethanol and [14C]oleic acid as substrates. Three isoenzymes, GST1, GST2 and GST3 which are members of the evolutionary classes mu, alpha, and pi, respectively, were studied and failed to show any significant synthesis of FAEE after 45 min incubation at 37 degrees C. FAEE synthase activity and GST3 activity in human placental extracts can be readily separated by ion exchange chromatography on DEAE cellulose. Thus the results show that FAEE synthase activity is not a feature of the major GSTs found in human tissues. The two FAEE synthase isoenzymes isolated by Bora et al. may have been co-purified with GST isoenzymes or these FAEE synthases may be members of the GST super family that have low specific activity in conventional GST assays and have not been previously described.
据报道，从人心肌中纯化出的两种脂肪酸乙酯（FAEE）合酶同工酶是谷胱甘肽S-转移酶（GST）[（1989年）《美国国家科学院院刊》86卷，4470 - 4473页；以及（1989年）《临床研究杂志》84卷，1942 - 1946页]。在本研究中，以乙醇和[¹⁴C]油酸为底物，检测了几种纯化且特性明确的人GST的FAEE合酶活性。分别研究了进化类别μ、α和π的三种同工酶GST1、GST2和GST3，在37℃孵育45分钟后，未显示出任何显著的FAEE合成。人胎盘提取物中的FAEE合酶活性和GST3活性可以通过在DEAE纤维素上的离子交换色谱轻易分离。因此，结果表明FAEE合酶活性并非人组织中主要GST的特征。Bora等人分离出的两种FAEE合酶同工酶可能是与GST同工酶共同纯化得到的，或者这些FAEE合酶可能是GST超家族的成员，在传统GST测定中具有低比活性且此前未被描述过。
