Gupta D K, Theisen N, von Figura K, Hasilik A
Biochim Biophys Acta. 1985 Nov 20;847(2):217-22. doi: 10.1016/0167-4889(85)90023-0.
Using metabolic labelling and sucrose density fractionation we compared the synthesis of lysozyme and lysosomal enzymes in human monocytic U937 cells. In pulse-chase experiments in sucrose density gradients, the intracellular radioactively labelled lysozyme distributed similarly to cathepsin D and beta-hexosaminidase. With the aid of immunochemical detection in Western blots, the steady-state distribution of lysozyme was found to be slightly different from that of beta-hexosaminidase; relatively more lysozyme was present in fractions sedimenting between lysosomes and the Golgi apparatus. The observed distribution of the lysozyme antigen with a prominent peak in the lysosomal fraction was in striking contrast to the broad distribution of the lysozyme activity. The difference was explained by a bias in the determination of the activity of lysozyme by the 'lysoplate' diffusion assay.
利用代谢标记和蔗糖密度梯度离心法，我们比较了人单核细胞U937细胞中溶菌酶和溶酶体酶的合成情况。在蔗糖密度梯度的脉冲追踪实验中，细胞内放射性标记的溶菌酶与组织蛋白酶D和β-己糖胺酶的分布相似。借助蛋白质免疫印迹法中的免疫化学检测，发现溶菌酶的稳态分布与β-己糖胺酶略有不同；在溶酶体和高尔基体之间沉降的组分中，溶菌酶的含量相对较多。溶菌酶抗原在溶酶体组分中出现显著峰值的分布情况，与溶菌酶活性的广泛分布形成了鲜明对比。这种差异可以通过“溶菌平板”扩散法测定溶菌酶活性时的偏差来解释。
