Human semen contains a large number of macromolecules, including proteins/enzymes and carbohydrates, regulating and protecting sperm cells. Proteomic analysis of human seminal fluid led to the discovery of semen amyloids derived from short peptide fragments of the proteins prostatic acid phosphatase (PAP) and semenogelin (SG) which are known to play a crucial role in enhancing HIV infection. However, the relevance of their existence in human semen and role in maintaining sperm behavior remains unclear. Distinct physiological, biochemical, and biophysical attributes might cause these amyloids to influence sperm behavior positively or negatively, affecting fertilization or other reproductive processes. We assessed the direct effect of amyloids derived from a PAP248-286 fragment, on sperm motility and viability, which are crucial parameters for assessment of sperm quality in semen. Co-incubation of human sperm with PAP248-286 amyloids at normal physiological concentrations formed in buffer led to significant reduction in sperm viability, though approximately a 10× higher concentration was needed to show a similar effect with amyloid formed in seminal fluid. Both forms of PAP248-286 amyloid also had a significant impact on sperm motility at physiological levels, in agreement with a previous report. Our study suggests that PAP248-286 amyloids can directly influence sperm motility and viability in a concentration-dependent manner. We hypothesise that the direct toxic effect of PAP248-286 amyloid is normally mitigated by other seminal fluid ingredients, but that in pathological conditions, where PAP248-286 concentrations are elevated and it plays a role in determining sperm health and viability, with relevance for male fertility as well as sterility.

中文翻译：

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精液淀粉样蛋白（SEVI）对精子活力和运动力的影响：对男性生殖健康的影响。

人精液含有大量的大分子，包括调节蛋白质和保护精子细胞的蛋白质/酶和碳水化合物。对人类精液的蛋白质组学分析导致​​发现了精液淀粉样蛋白，这种精蛋白淀粉样蛋白是由前列腺酸磷酸酶（PAP）和精液明胶（SG）的短肽片段衍生而来，已知这些蛋白在增强HIV感染中起关键作用。然而，它们在人类精液中的存在及其在维持精子行为中的作用的相关性仍不清楚。独特的生理，生化和生物物理属性可能导致这些淀粉样蛋白对精子的行为产生正面或负面影响，从而影响受精或其他生殖过程。我们评估了来自PAP248-286片段的淀粉样蛋白对精子活力和生存力的直接影响，这是评估精液精子质量的关键参数。人精子与在缓冲液中形成的正常生理浓度的PAP248-286淀粉样蛋白共同孵育会导致精子活力的显着降低，尽管需要大约10倍的更高浓度才能显示与精液中形成的淀粉样蛋白相似的作用。与先前的报告一致，两种形式的PAP248-286淀粉样蛋白在生理水平上也对精子活力具有重大影响。我们的研究表明，PAP248-286淀粉样蛋白可以浓度依赖的方式直接影响精子的活力和生存能力。我们假设，其他精液成分通常会减轻PAP248-286淀粉样蛋白的直接毒性作用，但在病理条件下，