Paju A, Bjartell A, Zhang W M, Nordling S, Borgström A, Hansson J, Stenman U H
Departments of Clinical Chemistry and Pathology, Helsinki University Central Hospital, Helsinki, Finland.
Am J Pathol. 2000 Dec;157(6):2011-21. doi: 10.1016/S0002-9440(10)64840-7.
Trypsinogen is a serine proteinase produced mainly by the pancreas, but it has recently been found to be expressed also in several cancers such as ovarian and colon cancer and in vascular endothelial cells. In this study, we found that trypsinogen-1 and -2 are present at high concentrations (median levels, 0.4 and 0.5 mg/L, respectively) in human seminal fluid and purified them to homogeneity by immunoaffinity and anion exchange chromatography. Purified trypsinogen isoenzymes displayed a M(r) of 25 to 28 kd in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. Most of the trypsinogen-1 purified from seminal fluid was enzymatically active whereas trypsinogen-2 occurred as the proform, which could be activated by enteropeptidase in vitro. Immunohistochemically, trypsinogen protein was detected in the human prostate, urethra, utriculus, ejaculatory duct, seminal vesicles, deferent duct, epididymal glands, and testis. Expression of trypsinogen mRNA in the same organs was demonstrated by in situ hybridization. Trypsinogen mRNA was also detected in the prostate and seminal vesicles by reverse transcriptase-polymerase chain reaction and Northern blotting. Isolated trypsin was shown to activate the proenzyme form of prostate-specific antigen. These results suggest that trypsinogen isoenzymes found in seminal fluid are produced locally in the male genital tract and that they may play a physiological role in the semen.
胰蛋白酶原是一种主要由胰腺产生的丝氨酸蛋白酶，但最近发现它也在几种癌症中表达，如卵巢癌和结肠癌，以及血管内皮细胞中表达。在本研究中，我们发现胰蛋白酶原-1和-2在人类精液中以高浓度存在（中位水平分别为0.4和0.5mg/L），并通过免疫亲和和阴离子交换色谱将它们纯化至同质。纯化的胰蛋白酶原同工酶在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和蛋白质印迹中显示出25至28kd的分子量。从精液中纯化的大多数胰蛋白酶原-1具有酶活性，而胰蛋白酶原-2以酶原形式存在，其在体外可被肠肽酶激活。免疫组织化学检测显示，在人类前列腺、尿道、前列腺囊、射精管、精囊、输精管、附睾腺和睾丸中可检测到胰蛋白酶原蛋白。通过原位杂交证实了同一器官中胰蛋白酶原mRNA的表达。通过逆转录-聚合酶链反应和Northern印迹也在前列腺和精囊中检测到了胰蛋白酶原mRNA。分离出的胰蛋白酶显示可激活前列腺特异性抗原的酶原形式。这些结果表明，精液中发现的胰蛋白酶原同工酶是在男性生殖道中局部产生的，并且它们可能在精液中发挥生理作用。
