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4668631 Process for producing a restriction enzyme
358
PATENT ABSTRACTS
assays with samples is substantially diminished. In accordance with one embodiment of the invention, the serum sample is treated with a sufficient amount of a peracid compound, either organic or inorganic, for a time and under conditions sufficient to reduce or eliminate background interference contributed by serum components other than analyte. The peracid compound is readily quenched, without adversely affecting the assay compositions. In another embodiment of the invention a liqand for the interfering component of the sample, such as unconjugated enzyme which is inactive but antigenic, is mixed with the sample to be analyzed. The presence of the liqand substantially reduces or eliminates background interference from components of the sample other than analyte.
An improved composition of the type comprising a known concentration of at least one enzyme. The composition is characterized in that substantially all of at least one of the enzymes is combined with a stabilizing amount of a reversible inhibitor thereof to form an inhibitorenzyme complex, thereby stabilizing the enzyme moiety of the complex. A method of stabilizing a composition comprising a known concentration of at least one enzyme. The method comprising combining substantially all of at least one of the enzymes with a stabilizing amount of a reversible inhibitor thereof to form an inhibitor-enzyme complex, thereby stabilizing the enzyme moiety of the complex. 4668631
4668623 METHOD OF FLUOROMETRICALLY MEASURING THE ACTIVITY OF FAT-DEGRADING ENZYMES Paavo K J Kinnunen, Tom Schroder, Jorma Virtanen, Espoo, Finland assigned to KSVChemicals Oy The object of the present invention is a new method for fluorometrically assaying the activity of fat-degrading enzymes, such as lipases and phospholipases in samples containing said enzyme, such as in serum, According to the method the enzyme containing sample is reacted with a substrate containing acyl- or alkylglycerols or phosphoglycerols having at least one fluorescent group, such as a pyrene group. The compounds may in addition contain flurorescence quenching groups. The enzyme hydrolyzes the substrate thus giving rise to changes in the fluorescence intensity during the enzyme reaction and the changes in the intensity are measured at a specific emission wavelength of the fluorescent group employed. The rate of change of the invensity is proportional to the enzyme activity in the sample. The invention concerns also the new compounds containing fluorescent groups to be used in the method.
4668630 STABILIZED ENZYMATIC COMPOSITION Allan L Louderback assigned to Beckman Instruments lnc
PROCESS FOR PRODUCING RESTRICTION ENZYME
A
Akira Obayashi, Nobutsug Hiraoka, Keiko Kita. Hiroshi Nakajima. Uji. Japan assigned to Takara Shuzo Co Ltd A restriction endonuclease having the ability to recognize the same base sequence and cleavage sites as Sacll and Sstll can be produced from Gluconobacter and isolated in pure form because no other restriction enzyme is formed.
4673647 PROCESS TO SOLUBILIZE ENZYMES AND AN ENZYME LIQUID PRODUCT PRODUCED THEREBY Charles E Brothers, Chong Y Kim assigned to Miles Laboratories Inc This invention relates to a novel process for the recovery of enzymes obtained from enzymeproducing microorganisms, and to the liquid enzyme product recovered by this process. Typically, the enzyme-containing filtrate from a fermentation of an enzyme-secreting microorganism is concentrated and a precipitation agent such as a salt or an organic solvent is added to the concentrate, thereby forming a cake. Then, a polyol solvent is circulated through the cake to solubilize the enzyme or enzyme complex from the cake and provide a liquid enzyme product. Particularly effective is propylene glycol as the polyol solvent. The liquid enzyme product may be shipped as is or subjected to further treat-
PATENT ABSTRACTS
assays with samples is substantially diminished. In accordance with one embodiment of the invention, the serum sample is treated with a sufficient amount of a peracid compound, either organic or inorganic, for a time and under conditions sufficient to reduce or eliminate background interference contributed by serum components other than analyte. The peracid compound is readily quenched, without adversely affecting the assay compositions. In another embodiment of the invention a liqand for the interfering component of the sample, such as unconjugated enzyme which is inactive but antigenic, is mixed with the sample to be analyzed. The presence of the liqand substantially reduces or eliminates background interference from components of the sample other than analyte.
An improved composition of the type comprising a known concentration of at least one enzyme. The composition is characterized in that substantially all of at least one of the enzymes is combined with a stabilizing amount of a reversible inhibitor thereof to form an inhibitorenzyme complex, thereby stabilizing the enzyme moiety of the complex. A method of stabilizing a composition comprising a known concentration of at least one enzyme. The method comprising combining substantially all of at least one of the enzymes with a stabilizing amount of a reversible inhibitor thereof to form an inhibitor-enzyme complex, thereby stabilizing the enzyme moiety of the complex. 4668631
4668623 METHOD OF FLUOROMETRICALLY MEASURING THE ACTIVITY OF FAT-DEGRADING ENZYMES Paavo K J Kinnunen, Tom Schroder, Jorma Virtanen, Espoo, Finland assigned to KSVChemicals Oy The object of the present invention is a new method for fluorometrically assaying the activity of fat-degrading enzymes, such as lipases and phospholipases in samples containing said enzyme, such as in serum, According to the method the enzyme containing sample is reacted with a substrate containing acyl- or alkylglycerols or phosphoglycerols having at least one fluorescent group, such as a pyrene group. The compounds may in addition contain flurorescence quenching groups. The enzyme hydrolyzes the substrate thus giving rise to changes in the fluorescence intensity during the enzyme reaction and the changes in the intensity are measured at a specific emission wavelength of the fluorescent group employed. The rate of change of the invensity is proportional to the enzyme activity in the sample. The invention concerns also the new compounds containing fluorescent groups to be used in the method.
4668630 STABILIZED ENZYMATIC COMPOSITION Allan L Louderback assigned to Beckman Instruments lnc
PROCESS FOR PRODUCING RESTRICTION ENZYME
A
Akira Obayashi, Nobutsug Hiraoka, Keiko Kita. Hiroshi Nakajima. Uji. Japan assigned to Takara Shuzo Co Ltd A restriction endonuclease having the ability to recognize the same base sequence and cleavage sites as Sacll and Sstll can be produced from Gluconobacter and isolated in pure form because no other restriction enzyme is formed.
4673647 PROCESS TO SOLUBILIZE ENZYMES AND AN ENZYME LIQUID PRODUCT PRODUCED THEREBY Charles E Brothers, Chong Y Kim assigned to Miles Laboratories Inc This invention relates to a novel process for the recovery of enzymes obtained from enzymeproducing microorganisms, and to the liquid enzyme product recovered by this process. Typically, the enzyme-containing filtrate from a fermentation of an enzyme-secreting microorganism is concentrated and a precipitation agent such as a salt or an organic solvent is added to the concentrate, thereby forming a cake. Then, a polyol solvent is circulated through the cake to solubilize the enzyme or enzyme complex from the cake and provide a liquid enzyme product. Particularly effective is propylene glycol as the polyol solvent. The liquid enzyme product may be shipped as is or subjected to further treat-