Human N-acetylgalactosamine-4-sulphatase: protein maturation and isolation of genomic clones

N-Acetylgalactosamine-4-sulphatase (EC 3.1.6.1, G4S) is composed of a 57 kDa species in human liver that dissociates into 43 kDa and 8 kDa subunits under reducing conditions and, when deficient, causes the lysosomal storage disorder, mucopolysaccharidosis type VI. We isolated genomic clones containing the G4S first exon, including the leader peptide and the amino terminus of the 43 kDa polypeptide. Amino-terminal amino acid sequences of the 43 kDa and 8 kDa subunits indicated that the 8 kDa component is linked to the 43 kDa polypeptide by a single disulphide bond, does not contain the mannose-6-phosphate lysosomal targeting signal and is at the carboxyl terminus of G4S.     

Positive identification of a lambda gt11 clone containing a region of fungal phytase gene by immunoprobe and sequence verification

Summary As the initial step in a project to provide a more cost-effective source of the phytase enzyme, this paper reports on the use of a polyclonal antibody raised to phytase purified from an isolate of Aspergillus niger (A. ficuum) to screen an A. niger lambda gt11 expression library and the use of amino acid sequencing to identify a clone containing part of the fungal phytase gene. The described use of amino acid sequence fragments to verify the cloning of a gene has potential applications in other cloning projects.Mention of a trademark or proprietary product does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply approval to the exclusion of other products that may also be suitable Offprint requests to: E. Mullaney     

Gastro-intestinal helminths of donkeys in Burkina Faso

Thirty adult donkeys from Burkina Faso were necropsied and their gastro-intestinal worm burdens counted and determined. The strongylids were the most abundant species with a prevalence of 100% for Strongylus vulgaris. Four species of Strongylus, two of Triodontophorus and six of the Cyathostominae were recovered. All of the animals were also infested with habronematid nematodes, but oxyurid and ascaridid nematodes were found in low numbers. In addition to the nematodes, the paramphistomid trematode Gastrodiscus aegyptiacus and the anoplocephalid cestode Anoplocephala magna occurred in varying numbers. Faecal egg-counts from 131 donkeys ranged between 100 and 9,200 for strongylid eggs.     

Differential modulation of rat heart mitochondrial membrane-associated enzymes by dietary lipid

Diets supplemented with high levels of saturated fatty acids derived from sheep kidney (perirenal) fat or unsaturated fatty acids derived from sunflower seed oil were fed to rats and the effect on heart mitochondrial lipid composition and membrane-associated enzyme behaviour was determined. The dietary lipid treatments did not change the overall level of membrane lipid unsaturation but did alter the proportion of various unsaturated fatty acids. This led to a change in the omega 6/omega 3 unsaturated fatty acid ratio, which was highest in the sunflower seed oil fed rats. Arrhenius plots of the mitochondrial membrane associated enzymes succinate-cytochrome c reductase and oligomycin-sensitive adenosinetriphosphatase (ATPase) after dietary lipid treatment revealed different responses in their critical temperature. For succinate-cytochrome c reductase, the critical temperature was 29 degrees C for rats fed the sheep kidney fat diet and 20 degrees C for rats fed the sunflower seed oil diet. In contrast, no shift in the critical temperature for the mitochondrial ATPase was apparent as a result of the differing dietary lipid treatments. The results suggest that the discontinuity in the Arrhenius plot of succinate-cytochrome c reductase is induced by some change in the physical properties of the membrane lipids. In contrast, mitochondrial ATPase appears insensitive, in terms of its thermal behaviour, to changes occurring in the composition of the membrane lipids. However, the specific activity of the mitochondrial ATPase was affected by the dietary lipid treatment being highest for the rats fed the sheep kidney fat diet. No dietary lipid effect was observed for the specific activity of succinate-cytochrome c reductase. This differential response of the two mitochondrial membrane enzymes to dietary-induced changes in membrane lipid composition may affect mitochondrial oxidative phosphorylation.