THE USE OF FORMALDEHYDE-TREATED 131I-ALBUMIN IN THE STUDY OF DIGESTIVE VACUOLES AND SOME PROPERTIES OF THESE PARTICLES FROM MOUSE LIVER
THE USE OF FORMALDEHYDE-TREATED 131I-ALBUMIN IN THE STUDY OF DIGESTIVE VACUOLES AND SOME PROPERTIES OF THESE PARTICLES FROM MOUSE LIVER
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甲醛处理的 131I-白蛋白在小鼠肝脏消化液泡和这些颗粒的一些特性研究中的应用
DOI：
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发表时间：
1967
影响因子：
7.8
通讯作者：
J. Donald McQueen
中科院分区：
文献类型：
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作者：
J. L. Mego;F. Bertini;J. Donald McQueen
小鼠肝颗粒（含经静脉注射的甲酰胺处理的131 I-白蛋白）孵育期间释放的三氯乙酸可溶性放射性几乎完全由131 I-碘酪氨酸组成。该物质被证明排泄到培养基中，而不是由于酸对颗粒的破坏。Triton X-100或培养基中不存在蔗糖抑制了颗粒相关标记蛋白的水解。这种抑制是由于消化空泡的破坏和悬浮培养基中蛋白质和组织蛋白酶的稀释。这些结果和其他实验证据有力地表明，含131 I-白蛋白的肝颗粒是消化空泡。结果还表明，131 I-白蛋白可用于研究这些空泡。高浓度的蔗糖（1 M）抑制颗粒内蛋白质的降解。然而，1 M盐抑制消化的速度。蔗糖有抑制作用的粗组织蛋白酶制剂，和盐刺激的活性时，131 I-白蛋白作为底物。因此，高蔗糖浓度作为消化泡内蛋白质水解的抑制剂的效果很可能主要是由于抑制了泡内的组织蛋白酶活性。盐的作用可能是由颗粒内和颗粒外组织蛋白酶活性的刺激引起的，尽管0.5-1.0 M KCl似乎可以保护颗粒。
The trichloroacetic acid-soluble radioactivity released during incubation of mouse liver particles containing intravenously injected formaldehyde-treated 131I-albumin consisted almost entirely of 131I-iodotyrosine. The material was shown to be excreted into the medium and was not due to disruption of the particles by acid. Triton X-100 or the absence of sucrose in the medium inhibited hydrolysis of the particle-associated labeled protein. This inhibition was due to disruption of the digestive vacuoles and dilution of the protein and cathepsins in the suspending medium. These results and other experimental evidence strongly suggest that the 131I-albumin-containing liver particles are digestive vacuoles. The results also establish that 131I-albumin may be used to study these vacuoles. High concentrations of sucrose (1 M) inhibited degradation of intraparticulate protein. However, 1 M salts inhibited only the rate of the digestion. Sucrose had an inhibitory effect on a crude cathepsin preparation, and salts stimulated the activity when 131I-albumin was used as substrate. The effect of high sucrose concentrations as an inhibitor of protein hydrolysis within digestive vacuoles was, therefore, most likely due principally to an inhibition of cathepsin activity within the vacuoles. The effect of salt was probably caused by a stimulation of both intra- and extra-particulate cathepsin activities, although 0.5–1.0 M KCl appeared to protect the particles.