Thetford C R, Morrell J M, Cockle S M
Department of Biochemistry and Physiology, University of Reading, U.K.
Biochim Biophys Acta. 1992 Jan 23;1115(3):252-8. doi: 10.1016/0304-4165(92)90062-y.
The novel peptide, pyroglutamylglutamylprolineamide (pGlu-Glu-ProNH2), has recently been isolated and characterized from the rabbit prostate complex. The tripeptide is present in high concentrations in the prostate complex and semen, together with a 40-50 residue polypeptide which contains a TRH-immunoreactive fragment at its C-terminus. The present study investigates changes in the levels of these TRH-related peptides in rabbits aged 11 weeks, 4 months, 7 months, 13 months and 2 years. For each age group the peptides were extracted from the prostate complex, separated by gel exclusion chromatography, and located by TRH radioimmunoassay. The TRH-immunoreactive fragment was released from the polypeptide by trypsin digestion prior to radioimmunoassay. Very low concentrations of TRH-immunoreactive peptides were present at 11 weeks of age, but considerable levels of both peptides were found in all the other age groups. Anion exchange chromatography, under conditions which resolve TRH and pGlu-Glu-ProNH2, showed that the majority of the low molecular weight TRH immunoreactivity co-eluted with synthetic pGlu-Glu-ProNH2. The remaining TRH immunoreactivity, which had not bound to the anion resin, also failed to bind to a cation exchange column at pH 2.0, indicating that it was not authentic TRH. Dissection of the prostate complex into its four constitutive regions (vesicular gland, coagulating gland, prostate and bulbourethral gland) followed by extraction, chromatography and TRH radioimmunoassay of each region showed that the TRH-related peptides were located in the prostate.
新型肽焦谷氨酰谷氨酰脯氨酰胺（pGlu-Glu-ProNH2）最近已从兔前列腺复合体中分离并鉴定出来。该三肽与一种40 - 50个残基的多肽一起，在前列腺复合体和精液中高浓度存在，该多肽在其C末端含有一个促甲状腺激素释放激素（TRH）免疫反应性片段。本研究调查了11周龄、4月龄、7月龄、13月龄和2岁兔子中这些TRH相关肽水平的变化。对于每个年龄组，肽从前列腺复合体中提取，通过凝胶排阻色谱法分离，并通过TRH放射免疫测定法定位。在放射免疫测定之前，通过胰蛋白酶消化从多肽中释放出TRH免疫反应性片段。11周龄时存在极低浓度的TRH免疫反应性肽，但在所有其他年龄组中都发现了相当水平的两种肽。在能分离TRH和pGlu-Glu-ProNH2的条件下进行阴离子交换色谱分析表明，大多数低分子量TRH免疫反应性与合成的pGlu-Glu-ProNH2共洗脱。其余未与阴离子树脂结合的TRH免疫反应性在pH 2.0时也未与阳离子交换柱结合，表明它不是真正的TRH。将前列腺复合体解剖成其四个组成区域（泡状腺、凝固腺、前列腺和尿道球腺），然后对每个区域进行提取、色谱分析和TRH放射免疫测定，结果表明TRH相关肽位于前列腺中。
