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Arylsulphatase from seminal plasma of fowl was characterized with a crude enzyme preparation using nitrocatechol sulphate as the substrate. Arylsulphatase activity was considerable and showed a shift of pH optimum dependent on the incubation time and on the presence of sulphate and chloride ions. The electrophoretic pattern of enzymic activity showed three separate bands. It is concluded that both arylsulphatases A and B may be present in seminal plasma.Among several enzymes of lysosomal origin found in fowl semen, arylsulphatase (EC 3.1.6.1) has not been detected thus far (McIndoe and Lake, '74). The present paper reports a considerable arylsulphatase activity in fowl seminal plasma. MATERIALS AND METHODSTwenty fowls (Gallus domesticus) of New Hampshire strain, aged 12 months, kept at the Test Station of Experimental Poultry, Zootechnical Institute, Chorzel6w, were used as the semen source. The animals were fed a commercial breeder's diet. Semen was collected according to Burrows and Quinn ('37).Semen collected from 20 fowls (approximately 10 ml) was centrifuged at 5,000 g for 120 min at 5°C. The obtained supernatant (seminal plasma containing approximately 7.5 mg protein per ml) was dialysed against distilled water (50-fold water volume excess with two water changes) and stored in the refrigerator. The enzymic activity of individual samples varied and usually showed a several-fold increase after the dialysis.Arylsulphatase activity of seminal plasma was determined according to Baum et al. ('58). Equal volumes of seminal plasma diluted eight times with distilled water) and 2 mN nitrocatechol sulphate (Sigma) in 0.5 M sodium acetate-acetic acid buffer with or without 1.7 M NaCl or 25 mM K2S04, adjusted to the appropriate pH (at room temperature) were mixed together and incubated at 37°C. Samples (0.5 ml) were withdrawn at suitable time intervals and added to 1.3 ml of 1 N NaOH.Optical density (OD) was read at 515 nm against appropriate blank sample using Specol photocolorimeter and cuvettes of 10-mm path length.Polyacrylamide gel electrophoresis at pH 8.9 was carried out according to Davis ('64) Bands with arylsulphatase activity were visualized by incubating the gels in 1 mM nitrocatechol sulphate in 0.25 M sodium acetateacetic acid buffer (pH 5.0) for 30 min at 37°C; gels were subsequently transferred to 1.0 N NaOH for 2-3 min and immediately photographed before the red bands had faded.Protein concentrations were determined according to Lowry et al. ('51). RESULTS AND DISCUSSIONSeminal plasma from fowl semen shows a marked arylsulphatase activity, the optimum pH of which is due to the incubation time and the presence of sulphate and chloride ions. In case of the reaction mixture containing substrate and seminal plasma in acetate buffer, there was a marked shift of pH optimum from pH 5.5 for 5-min incubation to pH 5.0 for 60 and 90 min incubation. If the reaction mixture contained additionally 12.5 mM KzS04, the enzyme activity was higher at more alkaline pH levels and again a time dependent shift of pH...

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