Enzymatic treatment of estrogens and estrogen glucuronide.

Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers. In this article, we investigated the enzymatic treatment of three estrogens (estrone, 17beta-estradiol, and 17alpha-ethynyletstradiol) by a fungal laccase which oxidize phenolic compounds with dissolved oxygen. The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay.

Oryzacystatin-II, a cystatin from rice (Oryza sativa L. japonica), is a dimeric protein: possible involvement of the interconversion between dimer and monomer in the regulation of the reactivity of oryzacystatin-II.

We examined the biochemical and structural properties of oryzacystatin-II, a phytocystatin in rice (Oryza sativa L. japonica), under heat-stress conditions. The enzyme inhibitory reactivity of oryzacystatin-II was enhanced by heating in a temperature-dependent manner and reached a maximum level by heating at 65 degrees C for 10 min.

Comparison of enzymatic and antifungal properties between family 18 and 19 chitinases from S. coelicolor A3(2).

Streptomyces coelicolor A3(2) has 13 chitinase genes encoding 11 family 18 and two family 19 chitinases. To compare enzymatic properties of family 19 chitinase and family 18 chitinases produced by the same organism, the four chitinases (Chi18bA, Chi18aC, Chi18aD, and Chi19F), whose genes are expressed at high levels in the presence of chitin, were produced in Escherichia coli and purified. The effect of pH on the hydrolytic activity was very different not only among the four chitinases but also among the substrates.

Distribution and phylogenetic analysis of family 19 chitinases in Actinobacteria.

In organisms other than higher plants, family 19 chitinase was first discovered in Streptomyces griseus HUT6037, and later, the general occurrence of this enzyme in Streptomyces species was demonstrated. In the present study, the distribution of family 19 chitinases in the class Actinobacteria and the phylogenetic relationship of Actinobacteria family 19 chitinases with family 19 chitinases of other organisms were investigated. Forty-nine strains were chosen to cover almost all the suborders of the class Actinobacteria, and chitinase production was examined.

Functional analysis of the chitin-binding domain of a family 19 chitinase from Streptomyces griseus HUT6037: substrate-binding affinity and cis-dominant increase of antifungal function.

Chitinase C (ChiC) is the first bacterial family 19 chitinase discovered in Streptomyces griseus HUT6037. While it shares significant similarity with the plant family 19 chitinases in the catalytic domain, its N-terminal chitin-binding domain (ChBD(ChiC)) differs from those of the plant enzymes. ChBD(ChiC) and the catalytic domain (CatD(ChiC)), as well as intact ChiC, were separately produced in E.

Family 19 chitinases of Streptomyces species: characterization and distribution.

Chitinase C from Streptomyces griseus HUT6037, described in 1997, is the first family 19 chitinase found in an organism other than higher plants. In this study, some properties of chitinase C were compared with those of family 18 bacterial chitinases, and the distribution of family 19 chitinases in Streptomyces species was investigated. The specific hydrolysing activity of chitinase C against soluble and insoluble chitinous substrates was markedly higher than those of bacterial family 18 chitinases.