ADP-RIBOSYLTRANSFERASE OF HELIOBACTER PYLORI

幽门螺杆菌是慢性胃炎的病原体十二指肠溃疡。和胃粘膜恶性肿瘤。探讨微生物致病因素。我们怀疑H。幽门螺杆菌产生ADP-核糖基转移酶（ART）以及抗溃疡药物是否能抑制该酶活性。对芽孢杆菌的超声培养物进行ART试验，其中浸提液与[腺苷酸-32 P]NAD孵育。当通过SDS-PAGE和放射自显影法分析试验混合物时，以MG 2+依赖性方式观察到细胞裂解物中70 kDa蛋白（P70）的放射性标记。P70的修饰似乎是由一个单一的艺术介导的，涉及非酶NAD依赖性修饰似乎是不可能的。观察到（ADP-核糖）-P70连接对羟胺处理敏感，精氨酸和胍基丁胺抑制P70的修饰，表明P70中的精氨酸残基是修饰的位点。此外，胍丁胺可以以MG 2+依赖性方式被假定的酶用作底物。H.幽门螺旋杆菌ART不被ARF激活，ARF是一种刺激霍乱毒素ART活性的小GTP结合蛋白。抗溃疡化合物瑞巴派特抑制H.幽门细胞裂解物。表明酶可能是药物的靶点。这些结果表明，H。幽门螺杆菌产生细胞相关的精氨酸特异性单抗，其对抗溃疡药物敏感。更进一步。H.用HL-60细胞的原核细胞裂解幽门螺杆菌，引起50 kDa蛋白质的修饰，表明该酶也能使宿主细胞蛋白ADP-核糖基化。由于许多细菌病原体产生的毒素具有单一的活性，结果可能表明，H。幽门螺杆菌艺术发挥作用的病理效应的钡。

HELICOBACTER PYLORI IS AN ETIOLOGIC AGENT FOR CHRONlC GASTRITIS. DUODENAL ULCERS. AND GASTRIC MUCOUS MALIGNANCY. TO VESTIGATE FACTORS INVOLVED IN THE PATHOGENESIS OF THE MICROORGANISM. WE EXAMlNED WHETHER H. PYLORI PRODUCES AN ADP-RIBOSYLTRANSFERASE (ART) AND WHETHER AN ANTI-ULCER DRUG CAN INHIBIT THE ENZYME ACTIVITY. SONIFIED CULTURE OF THE BACTERIA WAS SUBJECTED TO ART ASSAY IN WHICH THE EXTRACT WAS INCUBATED WITH [ADENYLATE-32P]NAD. WHEN THE ASSAY MIXTURE WAS ANALYZED BY SDS-PAGE AND AUTORADIOGRAPHY, RADIOLABELELLING OF A 70KDA PROTEIN (P70) IN THE CELL LYSATE WAS OBSERVED IN A MG2+-DEPENDENT MANNER. THE MODIFICATION OF P70 SEEMED TO BE MEDIATED BY A MONO-ART, AND INVOLVEMENT OF NON-ENZYMATIC NAD-DEPENDENT MODIFICATIONS APPEARED TO BE UNLIKELY. THE OBSERVATIONS THAT (ADP-RIBOSE)-P70 LINKAGE WAS SUSCEPTIBLE TO HYDROXYLAMlNE TREATMENT AND THAT ARGlNlNE AND AGMATINE INHIBITED THE MODIFICATION OF P70 INDICATED THAT ARGlNlNE RESIDUE IN P70 IS THE SITE OF THE MODIFICATION. ADDITIONALLY, AGMATINE COULD BE UTILIZED AS A SUBSTRATE BY THE PUTATIVE ENZYME IN A MG2+-DEPENDENT MANNER. H. PYLORI ART WAS NOT ACTIVATED BY ARF, A SMALL GTP-BINDlNG PROTEIN WHICH IS STIMULATE ART ACTIVITY OF CHOLERA ENTEROTOXlN. AN ANTI-ULCER COMPOUND, REBAMIPIDE, INHIBITED THE ADP-RIBOSYLATION BOTH OF P70 AND OF AGMATINE BY H. PYLORI CELL LYSATE. SUGGESTlNG THAT THE ENZYME CAN BE A TARGET OF THE DRUG. THESE RESULTS INDICATE THAT H. PYLORI PRODUCES A CELL-ASSOCIATED ARGlNlNE-SPECIFIC MONO-ART, WHICH IS SUSCEPTIBLE TO ANTI-ULCER DRUG. FURTHERMORE. INCUBATION OF H. PYLORI LYSATE WITH THE MOMOGENATE OF HL-60 CELLS CAUSED THE MODIFICATION OF A 50KDA PROTElN, SUGGESTING THAT THE ENZYME MAY ALSO ADP-RIBOSYLATE HOST CELL PROTEIN. BECAUSE MANY BACTERIAL PATHOGEN PRODUCE TOXINS WITH MONO-ART ACTIVITY, THE RESULTS MAY SUGGEST THAT H. PYLORI ART PLAYS A ROLE IN PATHOLOGICAL EFFECT OF THE BACTERlUM.