Ishiura S, Nomura Y, Tsukahara T, Sugita H
National Institute of Neuroscience, NCNP, Tokyo, Japan.
FEBS Lett. 1989 Oct 23;257(1):123-6. doi: 10.1016/0014-5793(89)81801-0.
A high-molecular mass ATP-dependent proteinase was shown to be identical to a multicatalytic proteinase, ingensin [(1988) Eur. J. Biochem. 177, 261-266]. The molecular mass of this proteinase increased in crude extracts of the rat liver and porcine brain, but not in the purified sample, only when the proteinase was extracted with ATP. The higher-molecular form of ingensin may be the intact one, because the concentration of ATP in vivo never decreases below 1 mM. This form of the proteinase is latent and it requires a high concentration of detergent for activation. On chromatography, it was found that the high-molecular form corresponds to the previously reported minor isoenzyme of ingensin [(1986) Biochim. Biophys. Acta 882, 297-304], ingensin A, or possibly to the ATP/ubiquitin-dependent 26S protease [(1987) J. Biol. Chem. 262, 8303-8313], and the low-molecular form to major ingensin B or the ATP/ubiquitin-independent 20 S protease.
一种高分子量的ATP依赖性蛋白酶被证明与一种多催化蛋白酶——英根辛相同[(1988)《欧洲生物化学杂志》177, 261 - 266]。只有当该蛋白酶用ATP提取时，这种蛋白酶的分子量在大鼠肝脏和猪脑的粗提物中会增加，但在纯化样品中不会增加。英根辛的高分子形式可能是完整形式，因为体内ATP的浓度从未降至1 mM以下。这种形式的蛋白酶是潜伏性的，它需要高浓度的去污剂来激活。在色谱分析中发现，高分子形式对应于先前报道的英根辛的次要同工酶[(1986)《生物化学与生物物理学报》882, 297 - 304]，即英根辛A，或者可能对应于ATP/泛素依赖性26S蛋白酶[(1987)《生物化学杂志》262, 8303 - 8313]，而低分子形式对应于主要的英根辛B或ATP/泛素非依赖性20S蛋白酶。
