title: Purification and properties of a human seminal proteinase.
abstract: 1. A method is described for the purification of a proteinase, present in human seminal plasma and previously shown to accelerate migration of spermatozoa through cervical mucus in vitro. A 25-fold purification was achieved in three steps, consisting of ammonium sulphate fractionation, chromatography on CM-cellulose and gel filtration. 2. The enzyme displays some properties similar to chymotrypsin: pH optimum 7.5-8.0; substrate preference of casein, haemoglobin and benzoyltyrosine ethyl ester but not benzoylarginine ethyl ester; mol.wt. 33000. However, it is unaffected by 1mm-di-isopropyl phosphofluoridate or 1mm metal cations, and in this respect differs from chymotrypsin. 3. The properties of the enzyme strongly resemble those of the ;chymotrypsin-like' enzyme discovered in seminal plasma by Lundquist et al. (1955). 4. The use of dimethyl-casein permitted the performance of enzyme assays at substrate concentrations five times higher (up to 50mg/ml) than could be achieved with ordinary casein (10mg/ml).
mesh_terms: D000645:Ammonium Sulfate; D011232:Chemical Precipitation; D002845:Chromatography; D002850:Chromatography, Gel; D002918:Chymotrypsin; D003911:Dextrans; D010450:Endopeptidases / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008722:Methods; D008970:Molecular Weight; D012661:Semen / Q000201:enzymology*; D013094:Spermatozoa
chemical_list: D003911:Dextrans; D010450:Endopeptidases; D002918:Chymotrypsin; D000645:Ammonium Sulfate