COCK SEMINAL PLASMA ACID-PHOSPHATASE - ACTIVE-SITE-DIRECTED INACTIVATION, CRYSTALLIZATION AND IN-VITRO DENATURATION-RENATURATION STUDIES

1. Seminal plasma acid phosphatase from the mini Rock cocks was purifi ed on a Sepharose 6B column and was not homogenous on polyacrylamide g el electrophoresis in the presence of sodium dodecylsulfate. Its stabi lity in time was also determined. 2. In the same time, the enzyme was crystallized in both ethanol and ammonium sulfate and this is also an evidence that this acid phosphatase was obtained in an advanced grade of purification but is present in a complex with some quantities of ot her proteins. 3. It was inactivated by iodoacetate to a degree consist ent with the modification of an active site residue. DTNB and thiosulf ate also inhibited this enzyme. 4. The enzyme was sensitive to 6 M gua nidinum hydrochloride which in the presence and absence of 0.25 M merc aptoethanol produces a deep loss of activity. After dialysis the activ ity was increased during the first 10 days up to 66.2% of the initial one. 5. In the presence of molar concentration of mercaptoethanol, the enzyme activity is deeply decreased, but it is partially restored aft er 120 hr when 1 mu M CuCl2 is added.