Actin in ejaculated human sperm cells.
Previous studies have identified an "actin-like" protein in human sperm by indirect immunofluorescence microscopy with various probes, but no real biochemical confirmation of actin was made. In this study, two-dimensional (2-D) gels of Nonidet P-40 (NP-40) extracts of purified human sperm cells revealed a protein with appropriate pI and molecular weight coordinates for actin. When excised from a 2-D gel, cleaved with N-chlorosuccinimide, and separated on a sodium dodecyl sulfate slab gel, this putative actin showed a cleavage pattern identical to those from known actin. Furthermore, when sperm were immediately purified from whole semen and extracted with 0.3% NP-40, actin was detected almost entirely in the soluble fraction, indicative of unpolymerized actin. Conclusions from these experiments support those implied by direct immunofluorescence microscopy: actin is present in human sperm and appears to be mainly unpolymerized.
D000199:Actins / Q000032:analysis / Q000378:metabolism*; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007526:Isoelectric Point; D008297:Male; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D013094:Spermatozoa / Q000378:metabolism*
D000199:Actins; D003902:Detergents; D010446:Peptide Fragments