Cytochemical localization and biochemical evaluation of a lysosomal serine protease in lung: dipeptidyl peptidase II in the normal rat.
Cytochemical localization and biochemical evaluation of a lysosomal serine protease in lung: dipeptidyl peptidase II in the normal rat.
复制标题
肺中溶酶体丝氨酸蛋白酶的细胞化学定位和生化评估：正常大鼠中的二肽基肽酶 II。
DOI：
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发表时间：
1985
影响因子：
3.2
通讯作者：
P. Sannes
中科院分区：
文献类型：
--
作者：
S. Randell;P. Sannes
Dipeptidyl peptidase II (DPP II) in normal rat lung was evaluated by the enzymes' ability to hydrolyze Lys-Ala or Lys-Pro derivatives of 4-methoxy-2-naphthylamine (MNA). For visualization of this activity, the liberated MNA was coupled with fast blue B for light microscopy (LM) or hexazotized pararosaniline with osmication for electron microscopy (EM). Granular to diffuse reaction product was noted in many lung cells in frozen sections for LM, including alveolar and tissue macrophages, fibroblasts, chondrocytes, bronchial and bronchiolar epithelial cells and mast cells. Reaction product at the EM level was seen in the lysosomal structures of the above cells, although lysosomal heterogeneity with regard to reactivity was noted. Cellular content of reaction product by EM correlated with LM staining intensity. Additional structures, not obviously reactive by LM, such as the lamellar bodies of type II cells and lysosomes in other cell types, were seen to contain reaction product ultrastructurally. A modified biochemical assay for the quantitation of DPP II in tissue homogenates was used to determine the activity of the enzyme in rat lung. Enzyme activity in polyacrylamide isoelectric focusing gels indicate that Lys-Ala-MNA was the more specific substrate but, by virtue of its rapid hydrolysis, Lys-Pro-MNA was more sensitive.
