IMMUNOREACTIVE UBIQUITIN IN HUMAN SEMINAL PLASMA

The polypeptide ubiquitin, up to now almost exclusively discovered in intracellular spaces, was measured immunologically in a total of 187 s amples of human seminal plasma. The values were between 1.83 and 19.11 mug/ml. In spermatozoa ubiquitin was detected too; the values, howeve r, were significantly lower than in the seminal plasma. The origin and function of ubiquitin in human seminal plasma is still unclear. The p ossible role of ubiquitin in reproduction is discussed.