Transformational Alteration of Human pancreatic Gamma-Glutamyl-transpeptidase (gamma-GTP)

为了阐明胰腺γ -谷氨酰胺转肽酶（γ - gtp）在恶性转化过程中的特异性变化，我们将胰腺癌纯化的γ - gtp与正常胰腺及其他组织的γ - gtp的一些特性进行了比较。5种胰腺癌γ - gtp中有4种的电泳迁移率明显低于正常酶。胰腺癌γ - gtps等电点在不同病例中有所不同，但均高于正常酶等电点。神经氨酸酶治疗减少了癌组织和正常组织之间γ - gtps等电点的差异。凝集素亲和层析显示，五种胰腺癌γ - gtp中有两种比正常胰腺γ - gtp对豆豆蛋白a （Con a）具有更大的亲和力。与正常胰腺γ - gtp相比，5种胰腺癌γ - gtp中有4种对culinaris凝集素（LCA）具有更大的亲和力。正常胰腺的γ - gtps对E-PHA的亲和力较弱，而5个胰腺癌的γ - gtps中有2个对E-PHA有明显的亲和力，1个对E-PHA有轻微的亲和力。这些结果表明，胰腺癌γ - gtp的转化变化主要发生在酶分子的糖链上，导致与正常胰腺酶相比，唾液酸含量较低，而聚焦和分割GlcNAc残基含量较高。此外，为了开发识别胰腺癌γ - gtp糖链特异性改变的单克隆抗体（MAb），我们利用杂交瘤技术制备了针对胰腺癌γ - gtp的单克隆抗体。所有单克隆抗体对来自胰腺癌和其他组织的γ - gtp均有反应，不能识别γ - gtp的糖链部分，只能识别γ - gtp的肽部分。这被认为是由于糖链的免疫原性可能比肽部分弱。我们正在准备特定的单克隆抗体，考虑一种新的设备。少

To elucidate the specific changes of pancreatic gamma-glutamltranspeptidase (gamma-GTP) associated with malignant transformation, some properties of gama-GTP purified from pancreatic cancer were compared with those of gamma-GTPs from normal pancreas and other tissues. Four of five pancreatic cancer gamma-GTPs showed distinctly slower electrophoretic mobility than the normal enzymes. Isoelectric points of pancreatic cancer gamma-GTPs varied in each case, but all of them were higher than those of normal enzymes. This difference in isoelectric points of gamma-GTPs between cancerous tissue and normal tissue was reduced by neuraminidase treatment. Lectin affinity chromatography revealed two of five pancreatic cancer gamma-GTPs with a greater affinity to concanavalin A (Con A) than normal pancreas gamma-GTPs. Four of five pancreatic cancer gamma-GTPs had a greater affinity to Lens culinaris agglutinin (LCA) than normal pancreas gamma-GTPs. Normal pancreas had little affinity to phaseolus vul … More garis erythroagglutinating (E-PHA), but two of five pancreatic cancer gamma-GTPs had an apparent affinity to E-PHA and one of them had a slight affinity to E-PHA. These results indicate that the transformational changes of pancreatic cancer gamma-GTP are mainly induced in the sugar chains of the enzyme molecules resulting in a lower content of sialic acid and higher content of fucose and bisecting GlcNAc residue as compared with the normal pancreatic enzymes.Furthermore, to develop the monoclonal antibody (MAb) that recognize the specific alteration of sugar chain of pancreatic cancer gamma-GTP, we prepared the MAb against gamma-GTP from pancreatia cancer using the hybridoma technique. All of the MAbs were reactive with gamma-GTPs from not only pancreatic cancers but also other tissues, and could not recognize sugar chain but peptide portion of gamma-GTP. This is considered to be due to the fact that the immunogenicity of sugar chain can be weaker in comparison with that of peptide portion. We are now preparing the specific MAb, considering a new device. Less