Roudani S, Pasqualini E, Margotat A, Gastaldi M, Sbarra V, Malezet-Desmoulin C, Lombardo D
INSERM U 260, Faculté de Médecine-Timone, Marseille/France.
Eur J Cell Biol. 1994 Oct;65(1):132-44.
Bile salt-dependent lipase (BSDL), an enzyme normally found in human pancreatic secretions is a 100 kDa glycoprotein. A BSDL-specific 477 bp cDNA probe was prepared by performing polymerase chain reaction experiments. This cDNA was used to probe mRNAs extracted from human pancreatic tissue and tumoral cell lines. Two mRNAs were detected in normal human pancreas at 2.2 and 1.3 to 1.5 kb. In human pancreatic tumoral cells, mRNAs encoding for the BSDL were detected using in situ hybridization, and proteins with an M(r) of 46,000 to 48,000 were translated into an in vitro system using mRNAs extracted from these cells. Using an immunoprecipitation procedure, we observed here that the specific BSDL polyclonal antibodies recognized three proteins of 100 +/- 5 (p100), 46 +/- 2 (p46) and 22.7 +/- 1.2 (p23) kDa, respectively in the soluble extracts of normal adult human pancreas. The p100 protein was probably the glycosylated product resulting from the translation of the 2.2 kb transcript. The p46 protein, which electrophoresed as a doublet was the main component immunoprecipitated from extract of a differentiated human pancreatic adenocarcinoma as well as from the extracts of two pancreatic cell lines, BxPC-3 and SOJ-6. In addition, the p46 immunoform of the BSDL was detected in cell-free medium from SOJ-6 cell line and its expression was found to be correlated with the secretion of an esterolytic activity on 4-nitrophenyl caproate, whereas the BxPC-3 cell line neither secreted the p46 nor showed any esterolytic activity on this substrate. The p46 may be either a short variant of BSDL resulting from the translation of the 1.3 to 1.5 kb transcript or a protein structurally related to the enzyme. The p46 doublet immunoform was detected in the human pancreatic secretion.
胆汁盐依赖性脂肪酶（BSDL）是一种通常存在于人体胰腺分泌物中的酶，是一种100 kDa的糖蛋白。通过聚合酶链反应实验制备了一种BSDL特异性的477 bp cDNA探针。该cDNA用于探测从人胰腺组织和肿瘤细胞系中提取的mRNA。在正常人胰腺中检测到两种mRNA，大小分别为2.2 kb和1.3至1.5 kb。在人胰腺肿瘤细胞中，使用原位杂交检测到编码BSDL的mRNA，并使用从这些细胞中提取的mRNA在体外系统中翻译出分子量为46,000至48,000的蛋白质。通过免疫沉淀程序，我们在此观察到，特异性BSDL多克隆抗体在正常成人胰腺的可溶性提取物中分别识别出三种蛋白质，分子量分别为100±5（p100）、46±2（p46）和22.7±1.2（p23）kDa。p100蛋白可能是由2.2 kb转录本翻译产生的糖基化产物。以双峰形式电泳的p46蛋白是从分化的人胰腺腺癌提取物以及两种胰腺细胞系BxPC-3和SOJ-6的提取物中免疫沉淀的主要成分。此外，在SOJ-6细胞系的无细胞培养基中检测到BSDL的p46免疫形式，并且发现其表达与对4-硝基苯基己酸酯的酯解活性分泌相关，而BxPC-3细胞系既不分泌p46，也未显示对该底物的任何酯解活性。p46可能是由1.3至1.5 kb转录本翻译产生的BSDL短变体，或者是与该酶结构相关的蛋白质。在人胰腺分泌物中检测到p46双峰免疫形式。
