Subcellular localization of blood group substances ABH in human salivary glands

We investigated the subcellular localization of ABH antigens in human submandibular, sublingual, and buccal glands by applying a post-embedding immunogold method using monoclonal antibodies specific for A, B, and H antigens. In most glands the immunoreactivity was usually restricted to mucous cells, in which only secretory granules and sometimes Golgi cisternae were specifically labeled. A and B antigens were demonstrated only in the glands of type A, B, and AB subjects, while H antigen was visualized in glands from individuals of all blood types. Moreover, differences were observed in the relative distribution of ABH antigens, depending on the type of gland.     

Frequencies of secretors and non-secretors of ABH group substances among 1,000 alcoholic patients

The ABO blood group and secretor status of 1,000 alcoholic patients has been determined. The patients were drawn from large alcoholic units in the London area together with several small units, including rehabilitation centres, nd 127 were from Aberdeen.The findings have been compared with appropriate controls which take into account the ethnic origin of the patients in the series. A striking disturbance of the secretor/non-secretor ratio among group A patients compared with the controls is observed. There is an increase in group A non-secretors, which is almost exactly balanced by a loss of group A secretors so that the overall frequency of the group A phenotype is not disturbed. It is difficult to find an acceptable explanation for these results.     

Studies on an antineoplastic fraction from human urine. Characterization of the major protein in this fraction.

A fraction has been isolated from human urine which exhibits antiproliferative activity against human tumour cell lines without affecting the growth of several normal diploid cell lines or tumour cells of mouse or hamster origin. The major protein present in this fraction has been characterized and tentatively designated antineoplastic urinary protein (ANUP). An S020,W value of 3.69 S was obtained by sedimentation velocity analysis, and a subunit molecular mass of 16 300 Da was obtained by sedimentation equilibrium and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Centrifugation data also indicated that the protein self-associates. The amino acid analysis of ANUP was consistent with its low pI (4.2) as determined by chromatofocusing analysis. Furthermore, the amino acid composition exhibited some features similar to collagen, as shown by high levels of proline and glycine, the absence of cysteine, and the presence of low levels of hydroxyproline.     

Thermal enzymes. IV. Partial separation of an adenosinetriphosphatase from an apyrase fraction

Adenosinetriphosphatase with a Q_P from 450 to 1400 was obtained from a cell granule fraction isolated from cells of a thermophilic bacterium. The enzyme withstands inactivation for 2 hr. at 65 °C., the growing temperature of the organism. At 75 °C. the enzyme is slowly inactivated. Magnesium plays a small part in providing protection against inactivation at 75 °C.     

Characterization of immunosuppressive substances in the basic protein fraction of uterine secretions from pregnant ewes

The basic protein fraction of ovine uterine secretions collected late in pregnancy (Days 125-140) contains a substance capable of inhibiting in vitro blastogenic responses of lymphocytes to phytohemagglutinin (PHA) or mixed lymphocyte reactions. In this study, the immunosuppressive substance in the basic protein fraction of uterine secretions was further defined by gel filtration. The immunosuppressive activity resided in a group of high molecular weight proteins eluting at the void volume of Sephacryl S-200 and Sepharose CL-6B columns. For example, incorporation of thymidine by PHA-stimulated lymphocytes incubated with 20, 40, 80, and 120 micrograms/ml of protein from the void volume of Sepharose CL-6B was 65, 28, 2, and 0 percent of control lymphocytes, respectively. Based on polyacrylamide-gel electrophoresis in the presence of sodium dodeylsulfate (SDS), the immunosuppressive fraction from Sepharose CL-6B chromatography contained aggregates of uterine milk proteins (UTM-proteins) and a pair of proteins running at the top of a 5% (w/v) polyacrylamide gel. Other protein peaks resolved by Sephacryl S-200 and Sepharose CL-6B contained aggregates of UTM-proteins but were not immunosuppressive. The substance inhibiting in vitro lymphocyte function was not of conceptus origin, because it was found in fluid from the ligated uterine horn of unilaterally pregnant ewes and from the uterus of an ovariectomized ewe treated for 60 days with progesterone and estrone.     

Preparation of an inner membrane-matrix fraction from yeast yeast mitochondria.

Treatment of yeast mitochondria with digitonin was used in order to prepare an inner membrane-matrix fraction preserving its permeability properties. The incubation time of mitochondria with digitonin was an essential parameter for the selective solubilization of the outer membrane. The incubation of mitochondria for l min at different concentrations of digitonin led to a three-step release of mitochondrial enzymes: (a) at low concentrations of digitonin, adenylate kinase was released; (b) higher concentrations were required to solubilize kynurenine hydroxylase, an outer membrane marker; (c) inner membrane markers (succinate dehydrogenase and oligomycin-sensitive adenosine triphosphatase) and matrix markers (fumarase and isocitrate dehydrogenase) were significantly released at concentrations of digitonin higher than 0.4 mg/mg of protein. The electron microscopic aspects of yeast mitoplasts (inner membrane-matrix fraction obtained by treatment with 0.4 mg of digitonin) showed an orthodox and a twisted configuration. These new organelles retained respiratory control when assayed with ethanol as the substrate. Their selective permeability properties were preserved as shown by isoosmotic swelling in potassium or ammonium salt solutions.     

Purification of an alkaline ribonuclease from soluble fraction of beef brain.

A ribonuclease (ribonucleate 3-pyrimidine-oligonucleotidohydrolase, EC 3.1.4.22) was purified 8300-fold from soluble fraction of beef brain and its properties were investigated. The enzyme is an endonuclease capable of hydrolyzing tRNA, rRNA, poly(C), but shows no activity towards poly(U), poly(A), and poly(G). The preparation is free of deoxyribonuclease, non-specific phosphodiesterase and phosphomonoesterase activity. The enzyme has a pH optimum of 7.6, is not heat stable, has a molecular weight of 25 000, and has a K-m of 134 mu rRNA and K-m of 1600 mug poly(C) per ml.     

Insights into the expression of ABH and Lewis antigens through human bone marrow transplantation.

Twelve information bone marrow transplants, with at least one difference in ABO and/or Lewis types between donor and recipient, were retrospectively studied. ABH and Lewis antigens were determined in plasma, erythrocytes, and lymphocytes. Donor lymphocytes acquired the ABH and Lewis antigens from the recipient's plasma in the same way that donor erythrocytes acquired the Lewis antigens from it. Lymphocytotoxicity detected type 1 ABH and Lewis antigens only, providing evidence for the existence of combined ABH and Lewis antigens on lymphocytes. This was in contrast with the ABH antigens on type 2 chains of red cells, which are devoid of Lewis specificities. The differences in genetic control, probable chemical structure, and cellular origin of these two types of ABH antigens are presented in a theoretical model that accounts for most of the known data.     

Purification of an adenylyl cyclase-containing plasma membrane fraction from Trypanosoma cruzi.

A fraction containing plasma membrane fragments has been purified from epimastigote forms of Trypanosoma cruzi. Cells were broken by sonic vibration under well defined conditions and membranes were isolated by differential centrifugation and equilibrium centrifugation in sucrose gradients. The co-purification (approximately 10-fold) of adenylyl cyclase and plasma membrane-bound radioactive iodine is highly suggestive of the localization of this enzyme in the plasma membrane of T. cruzi. Determination of succinate cytochrome c reductase and glucose-6-phosphatase activities, as well as of total amounts of DNA and RNA in the purified fraction, indicates a negligible contamination from other cellular organelles. The co-purification of acid phosphatase activity with bound labeled iodine and adenylyl cyclase was taken as circumstantial evidence that part of this enzyme also belongs to the plasma membrane of T. cruzi. Conventional electron miscroscopy and freeze-fracture images of this fraction are consistent with a highly enriched plasma membrane preparation.     

Preparation of an exopeptidase-enriched fraction from the hepatopancreas of decapods

A laboratory-scale process suitable for the large-scale recovery of exopeptidases from the hepatopancreas tissue of decapod viscera is described. A method for distinguishing the relative exopeptidase and endopeptidase activities of digestive proteases was developed and used to monitor the enrichment of exopeptidases in an endo- and exopeptidase mixture. Simple extracts of the digestive tissues from decapods were a rich source of proteolytic activity; however, they contain a relatively high ratio of endopeptidase to exopeptidase activity. Based on the finding that most of the endopeptidase activity of extracts was inhibited by serine proteinase inhibitors, the relative exopeptidase activity of crayfish and langostilla crab digestive proteases was enriched by Agarose-SBTI affinity chromatography.