Studies on epididymal sperm neuraminidase from boar, bull and rabbit
Neuraminidase was extracted from bull, boar and rabbit epididymal sperm by the following methods: sequential (hypotonic MgC12 and homogenization followed by detergent), acid (acetic acid and sonication followed by detergent) and acid-Brij (acetic acid and Brij-35 followed by Hyamine 2389 and Triton X-IOO). Sequential and acid extractions of rabbit epididymal sperm yielded little or no neuramidase activity. Of the total neuraminidase activity extracted by the acid-Brij method, 91% of the activity from rabbit epididymal sperm was detected in the acid-Brij extracts. The specific activity of the acid- Brij extracts was 5-fold higher than the extracted sperm pellet. Sequential or acid extracted, detergent-treated bull sperm exhibited specific activities 5 times greater than that of boar sperm treated in the same manner. The Hyamine and Triton extracts of acid-extracted bull and boar sperm, however, showed a 7-fold increase in specific activity compared to the detergent extracts of the sequential method. Thirty-seven percent of the total NANase activity of extracted boar epididymal sperm was observed in the acid-Brij extracts; however, 93% of the total activity was found in acid extracts. Purification of acid-Brij extracts of boar epididymal sperm by gel-filtration and affinity chromatography resulted in a purification factor of 28.9 with a total recovery of the enzyme; whereas, DEAE-Sephadex chromatography of oxamic acid column eluates increased the purity of neuraminidase 3.2 fold.