A . Kah, D . Dörnemann, and H . Senger Fachbereich Biologie/Botanik der Philipps-Universität Marburg, Lahnberge, D-3550 Marburg/L. , Bundesrepublik Deutschland Z . Naturforsch. 43c , 563-571 (1988); received March 3/Apr i l 12, 1988 C-5-Pathway, 4,5-Dioxovalerate, 5-Aminolevul inic Ac id , 4,5-Dioxovalerate Aminotransferase, Scenedesmus In the present paper the purif ication of a specific 4,5-d...

Identification of residues responsible for functional specificity in enzymes is a challenging and important problem in protein chemistry. Active-site residues are generally easy to identify, but residues outside the active site are also important to catalysis and their identities and roles are more difficult to determine. We report a method based on analysis of multiple sequence alignments, emb...

A case of a renal transplant recipient with colchicine-induced myopathy is presented. He was on colchicine therapy for 10 months. He was hospitalized for investigation of fatigue, severe myalgia in the lower extremities and elevated serum aminotransferase levels. His viral markers and other factors that may cause myalgia and that may increase the serum aminotransferase levels were either normal...

Isolation of organelles from broken-cell suspensions of phototrophically grown Euglena gracilis Klebs was achieved by isopycnic centrifugation on sucrose gradients. 2. Equilibrium densities of 1.23g/cm3 for peroxisome-like particles, 1.22g/cm3 for mitochondria and 1.17g/cm3 for chloroplasts were recorded. 3. The enzymes glycollate dehydrogenase, glutamate-glyoxylate aminotransferase, serineglyo...

Tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) enzyme and mRNA activity were not detectable in day 20 fetal rat liver. Precocious induction of catalytic activity by in utero injection of dibutyryl cAMP was a direct consequence of the de novo appearance of translatable tyrosine aminotransferase mRNA. In contrast, in utero injection of hydrocortisone acetate fa...

Addition of 1-3 mM-8-bromo-cyclic AMP to monolayer cultures of H-4 rat hepatoma cells resulted in a rapid but short-lived increase in tyrosine aminotransferase (EC 2.6.1.5) activity. The transient nature of this induction is due to desensitization to 8-bromo-cyclic AMP. Throughout this time course of induction and desensitization, removal of 8-bromo-cyclic AMP resulted in a rapid and significan...

Tyrosine aminotransferase was highly purified from rat livers in which the enzyme had been induced by a glucocorticoid hormone. The preparation eluted from a DEAEcellulose column as a single peak gave a single precipitin line by the Ouchterlony double diffusion precipitin reaction and sedimented as a single boundary in the ultracentrifuge with an s20,W of 5.9. A molecular weight of 91,000 was d...

The kinetics of transamination reactions catalyzed by pig heart “branched chain amino acid” aminotransferase was investigated. The activation of aged preparations by 2mercaptoethanol, previously noted, was associated with increases in both the maximum velocity and enzyme-substrate affinities. This implies a protein conformational change. The sharp pH optimum observed with standard assay conditi...