A counterpart of the antibody-mediated activation of genetically defective enzymes is reported here. Antibodies elicited by certain mutant forms of beta-D-galactosidase (EC 3.2.1.23) of Escherichia coli were found to inactivate the normal form of the enzyme. (Antibodies elicited by normal beta-D-galactosidase do not affect the enzyme's catalytic activity.) We present evidence that the inactivat...

A number of studies, mostly performed ex vivo, suggest that lysosomes are involved in apoptosis as a result of a release of their cathepsins into the cytosol. These enzymes could then contribute to the permeabilization of the outer mitochondrial membrane; they could also activate effector caspases. The present study aims at testing whether the membrane of liver lysosomes is disrupted during Fas...

All mammals lose their ability to produce lactase (β-galactosidase), the enzyme that cleaves lactose into galactose and glucose, after weaning. The prevalence of lactase deficiency (LD) spans from 2 to 15% among northern Europeans, to nearly 100% among Asians. Following lactose consumption, people with LD often experience gastrointestinal symptoms such as abdominal pain, bowel distension, cramp...

States of increased metabolic demand such as fasting modulate hypothalamic neuropeptide gene expression and decrease circulating leptin levels. This study tested the hypotheses that fasting stimulates gene induction mediated by cAMP response element (CRE)-dependent increases in gene transcription and that fasting-induced decreases in leptin can regulate this CRE-mediated gene induction. Using C...

introduction: it has been reported the alkaline response of pancreas to duodenal acidification is partly mediated through duodenal release of h2s, but till now the effect of duodenal acidification on gastric h2s release has not been investigated. therefore, the present study designed to evaluate the effects of duodenal acidification on gastric h2s release and level of mrna expression of cystath...

Different compositions of liquid media were used for their efficacy in the production of beta-galactosidase by Aspergillus oryzae in submerged fermentation. Enzyme production was improved by switching from lactose-based media to soybean meal- and wheat bran-based media. Further improvement was made when the soybean meal medium was supplemented with sodium nitrate and magnesium sulfate. Res...

When young and senescent erythrocytes, separated from freshly collected human blood, were incubated with 125I-goat anti-human IgG, binding of the IgG to the senescent cells was three times as high as that to the young cells. The release of the radioactivity from the anti-human IgG-bound senescent cells was enhanced by incubation with band 3 oligosaccharides but not by those digested with endo-b...

In this study, immobilization of partially purified almond (Amygdalus communis) β-galactosidase on Con A layered calcium alginate-cellulose beads was investigated. Immobilized β-galactosidase retained 72% of theinitial activity after crosslinking by glutaraldehyde. Both soluble and immobilized enzyme exhibited the samepH and temperature optima at pH 5.5 and 50ºC, respectively. Howev...

To optimize conditions for retroviral-mediated transfer of a recombinant gene to hepatocytes, the pMNSM-Tk-lacZ vector, which we had constructed to express the bacterial beta-galactosidase gene, was transduced to rat hepatocytes under various conditions, and the expression of beta-galactosidase activity was examined by cytochemical staining. Compared to the hepatocytes of adult rats, those of n...

A rapid and convenient assay system was developed to detect viable Escherichia coli in water. The target bacteria were recovered from solution by immunomagnetic separation and incubated in tryptic soy broth with isopropyl-beta-D-thiogalactopyranoside, which induces formation of beta-galactosidase in viable bacteria. Lysozyme was used to lyse E. coli cells and release the beta-galactosidase. Bet...