Abstract: The present invention relates to a method for measuring the activity of enzymes in a sample which contains at least one enzyme and at least one enzyme inhibitor corresponding to said enzyme, whereby after de-inhibition the activity of the released enzyme is measured in such a way that a substrate is added to the sample and the time course of the concentration of at least one reaction product (cleavage product) is recorded and the enzyme specific substrate has a fluorogenic part which is cleaved in the enzymatic reaction and the fluorescence (measuring parameter) of which can be detected in a wavelength range where the measuring parameter can be assigned unambiguously to the enzyme activity to be measured, whereby the de-inhibition is carried out by immersing a rigid carrier, to which the inhibitor binding substance is bound, into the sample. The present invention relates also to a corresponding device for measuring the activity on enzymes in a sample.

Abstract: A method for determining the activity of proteases is provided. Fluorogenic substrates from which the fluorogen 7-amino-4-trifluoromethylcoumarin is eliminated proved to be particularly advantageous for the activity measurement. These substrates make it possible for measurement in microtiter plates with a fluorescence reader and thus for the fluorimetric determination of such enzyme activities in blood serum.

Abstract: A method for determination of the potentially available activity of cathepsin B in a biological sample, including the activity of the active form of cathepsin B, the form of cathepsin B which can be activated from the pro-form procathepsin B being present in the sample, and the form of cathepsin B which can be activated and which is inhibited in the sample in its activity by protease inhibitor, whereby the procathepsin B being present in the sample is converted into the active form of cathepsin B, the free protease inhibitor for cathepsin B being present in the sample is depleted from the sample or its inhibitor function is suppressed, and the protease inhibitor is withdrawn from the inhibited form of cathepsin B, and subsequently the activity of the active cathepsin B in the sample is determined.

Abstract: The present invention relates to a method for measuring the activity of enzymes in a sample which contains at least one enzyme and at least one enzyme inhibitor corresponding to said enzyme, whereby after de-inhibition the activity of the released enzyme is measured in such a way that a substrate is added to the sample and the time course of the concentration of at least one reaction product (cleavage product) is recorded and the enzyme specific substrate has a fluorogenic part which is cleaved in the enzymatic reaction and the fluorescence (measuring parameter) of which can be detected in a wavelength range where the measuring parameter can be assigned unambiguously to the enzyme activity to be measured, whereby the de-inhibition is carried out by immersing a rigid carrier, to which the inhibitor binding substance is bound, into the sample. The present invention relates also to a corresponding device for measuring the activity on enzymes in a sample.

Abstract: A method and apparatuses for determining the total content of proteases by means of measuring their enzyme activity after previous deinhibition is disclosed. In biological samples, lysosomal proteases are completely (e.g. in blood serum) or partly (e.g. in tissue homogenates) inhibited. A method proposed for the deinhibition entails immersing a solid support material (e.g. nylon or nitrocellulose) as plastic strip to which is linked, covalently or by adsorption, an inhibitor-binding substance which binds the inhibitor corresponding to the protease more strongly than the protease in the sample for measurement. After the deinhibition has taken place, the plastic strip is removed from the liquid sample for measurement, and the sample for measurement is passed on for measurement of the enzyme activity. Fluorogenic substrates from which the fluorogen 7-amino-4-trifluoromethylcoumarin is eliminated proved to be particularly advantageous for the activity measurement.