An enzyme capture assay for analysis of active hyaluronan synthases.

We describe a sensitive assay for detection of active hyaluronan synthases (HASs) capable of synthesizing hyaluronan (HA) without use of radioactive uridine 5'-diphosphate sugar precursors. The HAS capture assay is based on the binding of a biotinylated HA binding protein (bHABP) to HA chains that are associated with HAS and the subsequent capture of bHABP-HA-HAS complexes with streptavidin-agarose. Specific HAS proteins (e.

Phospholipid dependence and liposome reconstitution of purified hyaluronan synthase.

Previous radiation inactivation and enzyme characterization studies demonstrated that the Streptococcus equisimilis hyaluronan synthase (seHAS) is phospholipid-dependent and that cardiolipin (CL) is the best phospholipid for enzyme activation. Here we investigated the ability of seHAS, purified in the absence of added lipid, to be activated by synthetic phosphatidic acid (PA), phosphatidylserine, or CL lipids containing fatty acyl chains of different length or different numbers of double bonds. The most effective lipid was tetraoleoyl CL (TO-CL), whereas tetramyristoyl CL (TM-CL) was ineffective.

N-glycosylation is not essential for enzyme activity of 11beta-hydroxysteroid dehydrogenase type 2.

11Beta-hydroxysteroid dehydrogenase (11beta-HSD) catalyzes the oxidation of cortisol and corticosterone to cortisone and 11-dehydrocorticosterone, respectively. NAD-dependent 11beta-HSD is expressed at high levels in the distal nephron and contributes to mineralocorticoid specificity in that region. The present studies determined whether N-glycosylation is necessary for the activity of NAD-dependent 11beta-HSD (11beta-HSD2).

Immunolocalization of NAD-dependent 11 beta-hydroxysteroid dehydrogenase in human kidney and colon.

The inactivation of physiological glucocorticoids by 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) confers mineralocorticoid specificity to certain aldosterone target tissues. Both NADP, and NAD-dependent isoforms of 11 beta-HSD have been described. An NAD-dependent isoform of 11 beta-HSD (11 beta-HSD2) was recently cloned from human kidney.

Synthesis of a new photoaffinity probe, 5-azido-[32P]UDPxylose, by UDPglucuronate carboxylyase from wheat germ.

The enzyme, UDPglucuronic acid carboxylase (EC 4.1.1.