Purification of apolipoprotein H(beta2-glycoprotein I)-like protein from human follicular fluid

We purified a glycoprotein of molecular weight 50 kDa that has an N-termina l sequence similar to that of apolipoprotein H indicating that it is identi cal to or highly homologous to apolipoprotein H. There are indications that apolipoprotein H or its homologue may be involved in the fertilization pro cess. Sperm motion was assessed employing computer-assisted semen analysis. The addition of the purified protein to prepared sperm samples from normos permic men increases significantly the straight line velocity (VSL) and the amplitude of lateral head displacement (ALH) but does not increase the num ber of progressively motile sperm. (C) 2001 Elsevier Science Inc. All right s reserved.