. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ATP-ASE OF MYTILUS SPERM RESULTS 297 Effects of the divalent cations. The mode of preparation of the sperm affects the response of the tail enzyme to the divalent cations, calcium and magnesium. This is illustrated in Figure 1, where the enzyme activity of preparations washed 3 times in FSW and once in M/2 KC1 is compared with that of sperm washed twice in FSW and 4 times in M/2 KC1. When the first washing procedure is followed, z o O <r O o 280 r 240 200 ,60 120 eo 40 ATP-ASE ACTIVITY OF MYTILUS SPERM TAILS EFFECT OF DIV
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ATP-ASE OF MYTILUS SPERM RESULTS 297 Effects of the divalent cations. The mode of preparation of the sperm affects the response of the tail enzyme to the divalent cations, calcium and magnesium. This is illustrated in Figure 1, where the enzyme activity of preparations washed 3 times in FSW and once in M/2 KC1 is compared with that of sperm washed twice in FSW and 4 times in M/2 KC1. When the first washing procedure is followed, z o O <r O o 280 r 240 200 ,60 120 eo 40 ATP-ASE ACTIVITY OF MYTILUS SPERM TAILS EFFECT OF DIVALENT CATIONS *,• WASHED 2XFSW-4XKCL A,0 WASHED 3XFSW-IXKCL. -I -2 -3 -4 LOG MOLAR -5 -6 C 0 N C . FIGURE 1. ATP-ase activity of Mytilus sperm tails. Effect of divalent cations. Sperm washed twice in filtered sea water (FSW) and 4 times in M/2 KC1 A, •. Sperm washed 3 times in FSW and once in M/2 KC1 A, O- Varying concentrations of MgCU A, A. Varying concentrations of CaCL • Q. Tube contents: M KC1, M veronal buffer pH , 8 X 10"4 M ATP, MgCl2 or CaCL, ml. sperm tail preparation; total ml. Incubation: 10 min., 27° C. Ordinate—% control P-liberation, abscissa—log molar concentration divalent cation. calcium inhibits in all concentrations, while the ATP-ase activity is maximal in 4 X 10~5 M MgCl2. Not only is the optimum for magnesium shifted to a higher con- centration, but calcium also now has a slightly activating effect on the enzyme when the latter method of washing is employed. Apparently a considerable amount of the divalent cations of the sea water remains with the residue when the sperm are washed only once in isotonic KC1 after repeated washing in FSW. Since Woods. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Ma
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