The Escherichia coli lacZ ochre mutant strain U118 was converted to an amber mutant and suppressed with supF, which inserts tyrosine. Enzymatically active beta-galactosidase was isolated. It contained tyrosine at residue number 17 instead of glutamic acid as in wild type.

This case report of the infantile form of Krabbe disease in a 2 1/2-month-old boy illustrates the complementary findings that may be seen on CT and MR scans. The key finding on the CT scan was increased density in a bilateral symmetrical distribution involving the thalami with extension into the centrum semiovale. The MR scan, on the other hand, more clearly showed demyelination in the brain st...

Glycosphingolipids are ubiquitous components of mammalian cell membranes, and defects in their catabolism by lysosomal enzymes cause a diverse array of diseases. Deficiencies in the enzyme β-galactocerebrosidase (GALC) cause Krabbe disease, a devastating genetic disorder characterized by widespread demyelination and rapid, fatal neurodegeneration. Here, we present a series of high-resolution cr...

Low levels of tetracyclines found as residues in milk inhibited the biosynthesis of beta-galactosidase in Escherichia coli. To produce the same effect, other antibacterials had to occur in concentrations that were more than 10-fold higher. This relative selectivity was exploited for the development of a screening test for tetracyclines in milk based on a chemiluminometric assay of beta-galactos...

Hexazinone [3-cyclohexyl-6-(dimethylamino)-l-methyl-l,Z,5-tria~in~2,4,(lH,ZH)-dione] was tested in the 2, 1, and 0.5 cc size uellet (10% ai) against very small stems [average height, 1.97m; average ground line diameter (GLD), 2 cm] of water oak, Quercus nigra L., at 1.12 and 2.24 kg/ha on a sandy loam soil. First year defoliation of water oak by the 0.5 cc pellet at 2.24 kg/ha was significantly...

Coimmobilization of beta-galactosidase and glucose oxidase in a redox polymer, polyvinylferrocenium perchlorate (PVF+ ClO4-), led to the development of an enzyme electrode for the determination of lactose. The amperometric response of the electrode was measured at +0.70 V vs. SCE, which was due to the electrooxidation of enzymatically produced H2O2. The effects of the substrate and buffer conce...

We describe a rapid and sensitive enzyme-linked immunosorbent assay (ELISA) for quantifying ferritin in human and rat biological fluids. We used chlorophenol red beta-D-galactopyranoside as the colorimetric substrate of beta-galactosidase (EC 3.2.1.23), which is coupled to specific antibodies to either human or rat liver ferritin. The assay is sensitive (detection limit for human assay = 0.58 m...

The initial rates of induced synthesis of tryptophanase, beta-galactosidase, and d-serine deaminase were measured in relation to the chromosome replication cycle of Escherichia coli B/r. Exponentially growing cultures were exposed briefly to (14)C-thymidine or the appropriate inducers (or both), and the amount of label or enzyme (or both) in cells of different ages was found by measuring these ...

Brachyury is required for the normal extension of the anteroposterior axis during mouse embryogenesis. A transgene comprising sequences from -500 to +150 relative to the start of Brachyury transcription, and the reporter gene lacZ, recapitulates some, but not all elements of Brachyury expression. Beta-Galactosidase expression is seen in the primitive streak from 6.5 d.p.c. but there is no detec...

During growth of streptomycin-dependent strains of Escherichia coli in the absence of streptomycin (deprived growth), both constitutive and inducible synthesis of beta-galactosidase were preferentially inhibited. A similar preferential inhibition of constitutive and derepressed synthesis of alkaline phosphatase was observed. Catabolite repression accounted for part, but not all, of the inhibiti...