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L Purzyc

Publications and source records attributed to L Purzyc.

7 recordsLinked to original sources
PubMed2001

The influence of mechlorethamine on the activity of ecto-ATPase of rat lymphocytes.

Mechlorethamine, is an immunomodulator widely used in therapy although its effect on plasma membrane - bound enzymes is unclear. In rats with an inflammatory state, an increased activity of ecto-ATPase was observed both in the B and T subpopulations of lymphocytes. A single administration of mechlorethamine (simultaneously with carrageenin - inflammation factor), either in immunomodulating (5microgram/kg) or cytotoxic (600microgram/kg) dose, decrease the enzymatic activity in both subpopulations but to higher degree in the case of cytotoxic dose. In in vitro studies, after administering mechlorethamine, a diminution of inhibiting potential of the inhibitors blocking the nucleophilic site of proteins was noticed. This confirms the hypothesis that mechlorethamine attacks the catalytic part of the ecto-enzyme containing a nucleophylic group. Classical inhibitors of apyrase - Hg(2+), cerythrosin B and suramine - did not cause any significant change in the activity of ecto-ATPase, what confirms the fact that these enzymes belong to different groups.

Adenosine Triphosphatases↗
PubMed1985

Alkaline phosphatase from human uterine myoma. II. Kinetic and immunological properties.

Thermostability of the purified alkaline phosphatase derived from human uterine muscle and myoma was established before and after desialization. Both enzymes were inhibited by sucrose, glucose and maltose in proportion to the carbohydrate concentration. L-Homoarginine inhibits the myoma enzyme in 90%, L-leucine, L-histidine and L-tryptophan in about 60%, and L-phenylalanine in less than 15%. The type of inhibition and Ki values were determined. Muscle and myoma enzymes cross-reacted with antisera against human liver and placental isoenzymes. Molecular and kinetic properties of the enzyme were compared with known human isoenzymes of alkaline phosphatase.

Alkaline Phosphatase↗
PubMed1984

Alkaline phosphatase from human uterine myoma. I. Purification and some properties.

Alkaline phosphatase from human uterine myoma was purified to homogeneity by butanol extraction, acetone precipitation, column chromatography on DEAE-cellulose, QAE-Sephadex and Con-A-Sepharose, gel filtration on Sephadex G-200 and preparative electrophoresis. The relative molecular mass (145 000), subunit mass (35 000), neutral sugars (7 micrograms/mg) and sialic acid (1 microgram/mg) content were estimated. pH optimum of the enzyme activity was 10.0-10.4, and Km for p-nitrophenyl phosphate was 0.23 mM. The enzyme was inhibited by Zn2+, phosphate, fluoride, EDTA and by treatment with neuraminidase. Mg2+ activated alkaline phosphatase and showed protective effect towards inhibition by EDTA and Zn2+. The uterine muscle alkaline phosphatase was also purified. It showed lower specific activity than myoma phosphatase, higher molecular mass (160 000) and subunit mass (76 400), higher neutral sugar and sialic acid content.

Alkaline Phosphatase↗
PubMed1979

ATP-ase activity and lipid content of erythrocytes in treatment of acute lymphoblastic leukemia in children.

In erythrocytes of children with the acute lymphoblastic leukemia the rise in total phospholipid content, confined predominantly to lecithin, the decrease of cholesterol/phospholipid ratio and the increase of the Mg++-activated ATP-ase activity was found prior to treatment. The abnormalities of the lipid composition were in general persistent also in remission. The activity of erythrocytes ATP-ase decreased to normal values after achievement of the reversion of clinical and hematological symptoms of the disease. The increase of the enzyme activity may be induced by the in vitro incubation of normal erythrocyte with the blood plasma of patients in the acute stage of lymphoblastic leukemia but not in remission.

Adenosine Triphosphatases↗
PubMedDate not supplied

Ecto-ATPase from rat lymphocytes--in vivo studies on the influence of levamisole.

Levamisole, known for a long time as an antiparasitic drug due to its immunomodulating properties, has been used in the therapy of immune disorders. The action of levamisole depends on the dose and the manner of administration, and it seems interesting to establish whether similar dependencies exist for the membrane enzymes of lymphocytes. Ecto-ATPase, the enzyme tightly integrated with cytoplasmic membrane, was chosen to examine these effects. The in vivo studies were conducted on rats with carragenine-induced inflammation. Levamisole was administered at two doses: high (2.5 mg/kg) and low (0.25 mg/kg), according to two schedules: a) at a single dose, simultaneously with carragenine, 24 h before or 24 h after induction of inflammation; the lymphocytes were collected five times every 24 h, and the activity of ecto-ATPase was determined; b) at four doses, every 24 h after carragenine injection; the lymphocytes were collected 120 h after the induction of inflammation. The results of our studies indicate that levamisole reduces the activity of ecto-ATPase in both populations of lymphocytes in vivo. An apparent deactivation of ecto-ATPase of lymphocytes T was observed when high doses of levamisole were administered four times. In the case of a single low dose of levamisole, the deactivating potential of this compound was not so evident, both for lymphocytes B and T. Different reactions of the enzyme from lymphocytes T and B to the levamisole observed in in vivo studies and different effects of inhibitors in vitro, suggest the dissimilarity of the structure of ecto-ATPases from both populations of lymphocytes.

Adenosine Triphosphatases↗