Krepela E, Procházka J, Mynaríková H, Kárová B, Polák J, Cermák J, Roubková H
Department of Molecular and Cellular Pneumology, Medical Faculty Hospital Bulovka, Prague, Czech Republic.
Int J Cancer. 1995 Mar 29;61(1):44-53. doi: 10.1002/ijc.2910610109.
In this study we have examined, by means of isoelectric focusing (IEF) in native polyacrylamide gel and contact-print fluorescence zymography, whether human lung carcinomas and the lung parenchyma contain different pools of multiple charge forms of the cysteine proteinase cathepsin B. The isoelectric point (pI) patterns of cathepsin B from lung carcinoma and matched lung were similar, particularly with regard to 2 major intermediate acidic enzyme pI forms designated as I and II (pIapp of 5.10 and 4.93 in tumors, and 5.11 and 4.94 in lungs, respectively). The slightly acidic cathepsin B pI forms (pIapp 5.47-5.19) in squamous-cell lung carcinoma (SQCLC) were significantly more numerous than such enzyme pI forms in lungs. The numbers of the highly acidic cathepsin B pI forms (pIapp 4.82-4.33) were significantly higher in SQCLC and lung adenocarcinoma (ACL) than in matched lung. The activity distribution percentage in the set of highly acidic cathepsin B pI forms was significantly higher in SQCLC and ACL than in matched lung. We also observed that cathepsin B from SQCLC and matched lung was fully recoverable by IEF from inhibition by leupeptin. Using the cysteine-proteinase-specific inactivator E-64, we revealed by IEF that some cathepsin B isoforms (charge forms) from SQCLC were more resistant to inactivation by this compound than the corresponding enzyme isoforms from lungs. After IEF, the enzyme isoforms apparently lost their resistance to E-64. Our results indicate that the pool of multiple charge forms of cathepsin B in SQCLC and ACL is different from that in the lung, and also that there may be an increased level of loose complexes between cathepsin B and some proteins or polypeptides in SQCLC compared to the lung.
在本研究中，我们通过在天然聚丙烯酰胺凝胶中进行等电聚焦（IEF）和接触印片荧光酶谱法，检测了人肺癌组织和肺实质中半胱氨酸蛋白酶组织蛋白酶B的多种电荷形式是否存在不同的库。肺癌组织和配对肺组织中组织蛋白酶B的等电点（pI）模式相似，特别是关于2种主要的中等酸性酶pI形式，分别命名为I和II（肿瘤中的表观pI为5.10和4.93，肺组织中分别为5.11和4.94）。肺鳞状细胞癌（SQCLC）中微酸性的组织蛋白酶B pI形式（表观pI 5.47 - 5.19）比肺组织中的此类酶pI形式明显更多。高酸性组织蛋白酶B pI形式（表观pI 4.82 - 4.33）的数量在SQCLC和肺腺癌（ACL）中显著高于配对肺组织。高酸性组织蛋白酶B pI形式组中的活性分布百分比在SQCLC和ACL中显著高于配对肺组织。我们还观察到，SQCLC和配对肺组织中的组织蛋白酶B通过IEF可完全从亮抑酶肽抑制中恢复。使用半胱氨酸蛋白酶特异性灭活剂E - 64，我们通过IEF揭示，SQCLC中的一些组织蛋白酶B同工型（电荷形式）比肺组织中相应的酶同工型对该化合物的灭活更具抗性。IEF后，酶同工型显然失去了对E - 64的抗性。我们的结果表明，SQCLC和ACL中组织蛋白酶B的多种电荷形式库与肺组织中的不同，并且与肺组织相比，SQCLC中组织蛋白酶B与某些蛋白质或多肽之间的松散复合物水平可能升高。
