Protein abundances matrix

Protein abundance was then estimated using a traditional label-free, intensity-based absolute quantification (iBAQ) algorithm, which divided the protein abundance (derived from intensities of the identified peptides) by the number of theoretically observable peptides. Fraction of total (FOT) is a relative quantification value defined as a protein’s iBAQ divided by the sum of the iBAQ of all proteins identified in an experiment, calculated as the normalized abundance of a particular protein in the experiment. Finally, for the ease of presentation, the FOT was further multiplied by 1e5.

随后采用传统无标记（label-free）基于强度的绝对定量（intensity-based absolute quantification, iBAQ）算法估算蛋白质丰度：该算法将由鉴定到的肽段强度推导得到的蛋白质丰度，除以理论上可检测的肽段数量。总占比（Fraction of total, FOT）是一种相对定量值，其定义为某蛋白质的iBAQ值与单次实验中鉴定到的所有蛋白质的iBAQ值总和的比值，计算结果等价于该实验中特定蛋白质的标准化丰度。最后，为便于结果呈现，将FOT值进一步乘以1×10^5（即1e5）。