Singh Bhanu Pratap, Saha Ishita, Nandi Indrani, Swamy Musti J
School of Chemistry, University of Hyderabad, Hyderabad, 500046, India.
School of Chemistry, University of Hyderabad, Hyderabad, 500046, India.
Biochem Biophys Res Commun. 2017 Dec 2;493(4):1418-1424. doi: 10.1016/j.bbrc.2017.09.148. Epub 2017 Sep 28.
The major bovine seminal plasma protein, PDC-109, binds to choline phospholipids of the sperm plasma membrane and induces an efflux of cholesterol and choline phospholipids (cholesterol efflux), which is crucial for sperm capacitation. PDC-109 also exhibits chaperone-like activity and protects target proteins against various kinds of stress. Here we show that the polyamines spermine and spermidine, present in high concentration in the seminal plasma of various mammals, increase the ability of PDC-109 to perturb membrane structure as well as its chaperone-like activity. Interestingly, spermine/spermidine alone did not perturb membrane structure but exhibited chaperone-like activity by protecting target proteins against thermal and oxidative stress. When spermine/spermidine was used along with PDC-109, the observed chaperone-like activity was considerably higher than that expected for a simple additive effect, suggesting that PDC-109 and the polyamines act in a synergistic fashion. These results indicate that at the high concentrations present in the seminal plasma spermine/spermidine exhibit a positive modulatory effect on the chaperone-like activity of PDC-109 and may also function as chemical chaperones and protect other seminal plasma proteins from various kinds of stress.
主要的牛精浆蛋白PDC - 109与精子质膜的胆碱磷脂结合，并诱导胆固醇和胆碱磷脂外流（胆固醇外流），这对精子获能至关重要。PDC - 109还表现出类似伴侣蛋白的活性，并保护靶蛋白免受各种应激。在此我们表明，在各种哺乳动物的精浆中高浓度存在的多胺精胺和亚精胺，增强了PDC - 109扰乱膜结构的能力及其类似伴侣蛋白的活性。有趣的是，单独的精胺/亚精胺不会扰乱膜结构，但通过保护靶蛋白免受热应激和氧化应激而表现出类似伴侣蛋白的活性。当精胺/亚精胺与PDC - 109一起使用时，观察到的类似伴侣蛋白的活性明显高于简单加和效应所预期的，这表明PDC - 109和多胺以协同方式起作用。这些结果表明，在精浆中高浓度存在的精胺/亚精胺对PDC - 109的类似伴侣蛋白的活性表现出正向调节作用，并且还可能作为化学伴侣蛋白发挥作用，保护其他精浆蛋白免受各种应激。
