Fig. 1.

Design for detergent extraction of the inner acrosomal membrane (IAM, designated by a line) and its extracellular protein coat (IAMC, designated by beads) from sonicated and isolated sperm heads (SSpH). The detergent extract is separated from the SSpH by centrifugation and analyzed for protein and enzyme content by conventional and gelatin zymogram polyacrylamide gel electrophoresis (PAGE). Distinctive enzymatic activity is found at both the 72- and -35 kDa levels. Gel lanes were loaded with non-ionic (NP-40) and ionic (RIPA) detergent extracts, giving essentially the same results. PM plasma membrane; OAM outer acrosomal membrane; ES equatorial segement; SL subacrosomal layer (red); PS postacrosomal sheath (yellow). Isolation of the IAM and IAMC was based on protocol previously published by Yu et al. (2006)