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Gluten-free wheat bran and bread drink were produced by degrading gluten with Aspergillus niger prolyl endopeptidase (AN-PEP). For this purpose, bran from native and germinated wheat grains as well as bread drink were mixed with AN-PEP and incubated at 50°C under different conditions. The amount of enzyme activity (1.2 • 10-4-8.7 • 10-1 U), the incubation time (0-72 h), and the pH value (1.0-9.0) were systematically altered. The gluten content was monitored by a competitive ELISA using the R5 antibody. Gluten in two wheat bran samples produced in the laboratory was degraded below the threshold for gluten-free foods of 20 mg/kg. This was not possible in a commercial wheat bran sample that had potentially been heat-treated leading to strong crosslinking of gluten by incorporation of gliadins into the glutenin fraction, possible formation of isopeptide crosslinks and, thus, poor digestibility. In contrast, gluten in bread drink was easily degraded after a short incubation time of 30 min and low AN-PEP activity. No significant differences of the quality parameters between treated and untreated products were found. Remarkably, bran from germinated grains was strongly enriched in nutritionally positive compounds such as dietary fiber and folates compared to native grains. Thus, wheat bran from germinated grains rendered gluten-free by treatment with AN-PEP can contribute to increasing the nutritional value of the gluten-free diet.

Congenital nonspherocytic hemolytic anemia in an adult male of Scandinavian ancestry was associated with virtual absence of G6PD activity in red cells. Characterization of G6PD purified from leukocytes using standard WHO techniques revealed diminished electrophoretic mobility, marked lability on heating at 46 degrees C, normal pH optimum and utilization of alternate substrates (2-deoxy G6P, D-amino NADP), elevated Km NADP, and striking susceptibility to NADPH inhibition. The variant G6PD, which appears to be unique, has been designated G6PD San Francisco. An unusual feature of the variant enzyme, susceptibility to inactivation by brief periods of dialysis, could be prevented by addition of 200 microM NADP to the dialysis solution. In red cells, where G6PD activity was essentially absent, regeneration of reduced glutathione was totally curtailed in vitro, while in leukocytes, where residual G6PD activity was approximately 60% of normal, hexose monophosphate shunt activity, oxygen consumption during phagocytosis, and bacterial killing were unimpaired. Thus, instability of the variant enzyme rather than its unfavorable kinetics appeared to be an important determinant of abnormal cell function.