Abnormal physical architecture of the lipophilic domains of human sperm membrane in oligospermia: a logical cause for low fertility profiles.

Three different domains of human sperm membrane, viz., the hydrophobic domains, the aqueous compartments and the surface proteins were probed to evaluate the molecular dynamics in these microenvironments in normal as well as oligospermic cases. Decreased rotational motion of the stearic spin-labels, designated rigid lipid matrix affording hindrance to the protein rotation in spermatozoa of oligospermic patients. The intrinsic tight anchoring of thiol containing proteins led to their increased ordering on the spermatozoa of such individuals. Fluorescence polarization studies revealed weaker hydrophobicity around these sperm proteins in oligospermia. Thus, this study identifies abnormal molecular mobility in the limiting membranes of oligospermic cells.