No abstract

Nuclear matrix prepared from 2-3 week old rat thymuses contains tightly bound TdT activity which has been quantitatively solubilized with nonionic detergent and sonication. TdT is contained in a discrete complex with a sedimentation value of 23 S. The complex is retained on an anti-TdT antibody column and contains DNA ligase and 3'-5' exonuclease activities as well as DNA and several other proteins but is devoid of replicative DNA polymerases. Such a type of multienzyme complex is absent from the nuclear extracts of thymus prepared from older rats and also from liver and spleen extracts of young and old rats.

No abstract

The effect of procaine hydrochloride, an anesthetic known to alter membrane structure, on the induced formation of alkaline phosphatase, a periplasmic enzyme, in Escherichia coli was investigated. Procaine hydrochloride specifically arrested the appearance of active alkaline phosphatase while permitting the induction of another enzyme, beta-galactosidase, which is internally localized. Evidence has been obtained to show that procaine hydrochloride does not arrest synthesis of inactive monomer subunits of the enzyme, indicating that the drug interferes in the conversion of monomer subunits to an active dimer enzyme.

We evaluated the efficacies of five treatment procedures for eliminating ascorbate interference in the enzymatic determination of urinary oxalate. Aliquots of urine samples, containing different amounts of added ascorbate and oxalate, were individually subjected to ferric chloride, sodium nitrite, sodium periodate, charcoal, or ascorbate oxidase treatment to eliminate ascorbate interference. Oxalate contents of the urine samples were then determined by a banana oxalate oxidase-horseradish peroxidase-linked assay with 3-methyl-2-benzothiazolinone hydrazone and 3-(dimethylamino)benzoic acid as chromogens. Only those urine samples treated with ascorbate oxidase or charcoal consistently gave recovery of oxalate close to 100%. Treatment with other reagents, though improving the recovery of oxalate, gave inconsistent results. On the basis of these data, we describe procedures for simply and reliably assaying oxalate by using banana oxalate oxidase.