1. 1.|The instantaneous addition of phospholipase C to goldfish brain inner mitochondrial vesicles resulted in a partial loss of ferricyanide reduction. The retained activity rose when the phospholipase concentration and incubation period were increased.
2. 2.|No impairment of ferricyanide reduction was observed when Antimycin A-treated inner membrane vesicles were incubated with the phospholipase at 0.05 and 0.2 U mg?1 to 20 min. However, higher concentrations of the hydrolytic enzyme caused a considerable elevation in reduction and is attributed to a deterioration in vesicular integrity.
3. 3.|The hydrolysis of phospholipids from the inner membrane revealed that the phospholipase, at concentrations above 0.2 U mg?1 (minimum of 10 min incubation), resulted in removal of over 50% lipid phosphate. It was suggested that the phospholipase, at such levels, is accessible to the interior of the vesicles.
4. 4.|With the exception of cardiolipin and phosphatidyl inositol, the phospholipase was observed to be non-specific to the phospholipids from mitochondrial inner membrane treated with Triton X-100.
5. 5.|The phospholipids are asymmetrically arranged across the inner membrane and their distribution is dependent on acclimation temperature.
6. 6.|It is suggested that the compositional redistribution of the phospholipids, when acclimation temperature was changed, is necessary to stabilize the bilayer conformation of the membrane in concurrence with maintaining fluidity and functional capacity.
Author Keywords: Phospholipase C; phospholipid; mitochondria; mitoplast; submitochondria; goldfish
