Carrell D T, Hammond M E, Odell W D
Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132.
Endocrinology. 1993 Mar;132(3):1085-9. doi: 10.1210/endo.132.3.7679968.
In the human and all other mammalian systems studied, LH and hCG bind to a common high affinity receptor with equal affinity. We have recently reported that a unique high affinity binding site in Xanthomonas maltophilia preferentially binds hCG and a native CG-like ligand over LH or other glycoprotein hormones. In the current studies, we have analyzed the effect of hCG or the native ligand on culturing Xanthomonas maltophilia. Both the human and native ligand caused a dose-dependent alteration in the pattern of the growth cycle and a change in the morphology of the bacteria during the stationary phase of the growth cycle. The protein concentration reached during the stationary phase was significantly (P < 0.005) higher in cultures supplemented with hCG or the native ligand. When an aliquot of the culture was diluted and plated on Earl's Martin Balanced agar plates, the number of subsequent colonies was increased (P < 0.02) in the fractions supplemented with the ligands. The increased growth was significant (P < 0.05) to the lowest concentration of 50 ng/ml ligand. When grown under partially anaerobic conditions, the effects of hCG were observed earlier in the growth cycle. The active hormones, hCG and native ligand, also changed bacterial morphology. These data indicate that hCG may have an autocrine and/or paracrine function in bacteria.
在已研究的人类及所有其他哺乳动物系统中，促黄体生成素（LH）和人绒毛膜促性腺激素（hCG）以相同亲和力与一种共同的高亲和力受体结合。我们最近报道，嗜麦芽窄食单胞菌中一个独特的高亲和力结合位点优先结合hCG和一种天然的类绒毛膜促性腺激素配体，而非LH或其他糖蛋白激素。在当前研究中，我们分析了hCG或天然配体对嗜麦芽窄食单胞菌培养的影响。人源配体和天然配体均导致生长周期模式出现剂量依赖性改变，以及在生长周期的稳定期细菌形态发生变化。在添加了hCG或天然配体的培养物中，稳定期达到的蛋白质浓度显著更高（P < 0.005）。当取一份培养物稀释后接种到厄尔氏马丁平衡琼脂平板上时，添加配体的组分中后续菌落数量增加（P < 0.02）。配体浓度低至50 ng/ml时，生长增加仍显著（P < 0.05）。在部分厌氧条件下培养时，hCG的作用在生长周期中出现得更早。活性激素hCG和天然配体也改变了细菌形态。这些数据表明，hCG在细菌中可能具有自分泌和/或旁分泌功能。
