Analysis of the Sperm Head Protein Profiles in Fertile Men: Consistency across Time in the Levels of Expression of Heat Shock Proteins and Peroxiredoxins

We investigated the identity and quantitative variations of proteins extracted from human sperm heads using a label-free Gel-MS approach. Sperm samples were obtained from three men with high sperm counts at three different time points. This design allowed us to analyse intra-individual and inter-individual variations of the human sperm head proteome. Each time point was analyzed in triplicate to minimize any background artifactual effects of the methodology on the variation analyses. Intra-individual analysis using the spectral counting method revealed that the expression levels of 90% of the common proteins identified in three samples collected at various time-points, separated by several months, had a coefficient of variation of less than 0.5 for each man. Across individuals, the expression level of more than 80% of the proteins had a CV under 0.7. Interestingly, 83 common proteins were found within the core proteome as defined by the intra- and inter-variation analyses set criteria (CV

本研究采用无标记凝胶质谱（label-free Gel-MS）技术，对人类精子头部提取的蛋白质的组成与定量差异开展了系统探究。研究样本取自3名精子浓度偏高的男性，分别在三个不同时间点采集其精子样本。该实验设计可用于分析人类精子头部蛋白质组（proteome）的个体内与个体间差异。为最大程度降低实验方法本身的背景伪影效应对差异分析的干扰，每个时间点的样本均设置三次重复分析。采用光谱计数法（spectral counting method）开展个体内差异分析结果显示，针对每名受试者，在间隔数月采集的三份不同时间点样本中鉴定出的共有蛋白质里，90%的蛋白质表达水平的变异系数（coefficient of variation, CV）均小于0.5。在个体间的比较中，超过80%的蛋白质的表达水平的变异系数均低于0.7。值得注意的是，依据个体内与个体间差异分析的设定标准，在核心蛋白质组中鉴定出了83种共有蛋白质，其变异系数（CV