Recombinant yeast assay

Dioxin-like activity was assessed by the AhR recombinant yeast assay (AhR-RYA) performed as described in Noguerol et al. [79]. BP1, with an EC50 value of 0.61 mg/L showed tenfold more dioxin-like activity than BP3, with an EC50 value of 6.8 mg/L. However, two of their metabolites, 4HB and DHMB, presented 4 and 11 times higher activities, with EC50 values of 0.16 and 0.59 mg/L, respectively. No dioxin-like activity was observed for either 4DHB or THB. 

Routledge, E.J. and Sumpter, J.P. (1996). Estrogenic activity of surfactants and some of their degradation products assessed using a recombinant yeast assay. Environmental Toxicology and Chemistry, 15 241-248. 

No estrogenic activity of an ethanol extract of polygala was observed in a recombinant yeast assay system with a human estrogen receptor expression plasmid and a reporter plasmid (Kim et al. 2008). 

Boldrin PK, Resende FA, Hohne APO, de Camargo MS, Espanha LG, Nogueira CH, et al. Estrogenic and mutagenic activities of Crotalaria pallid measured by recombinant yeast assay and Ames test. BMC Compl Alternative Med 2013 13 216. 

Cespedes, R. Petrovic, M. Raldua, D. Saura, U. Pina, P. Lacorte, S. Viana, P. Barceld, D. Integrated procedure for determination of endocrine-disrupting activity in surface waters and sediments by use of the biological technique recombinant yeast assay and chemical analysis by LC ESI MS. Anal. Bioanal. Chem. 2004, 378, 697-708. 

Coldham NG, Dave M, Silvapathasundaram S, McDonnell DP, Connor C, Sauer MJ (1997) Evaluation of a recombinant yeast cell estrogen screening assay. Environ Health Perspect 105 734-742... 

In Table 6 the physico-chemical properties, chemical structures, and some other relevant data of some natural estrogens, synthetic estrogens, and of some environmental man-made EDCs are compiled, as is the estrogenic activity measured as the relative proHferative potency on human breast cancer MCE 7 cells in the E-SCREEN assay [136] and in the recombinant yeast cell estrogen screening assay (RCBA) [138b]. In the last column of Table 6 their occurrence in the aquatic environment and their bioconcentration factors in fish and mussels are presented also as far as these data were pubHshed. 

Another much used yeast-based assay is the yEGFP assay (first described by Bovee et al., 2004). In this assay recombinant yeast cells are constructed that express the human estrogen reporter a (ER a) and yeast enhanced green fluorescence protein), the estrogenic potential is then measured by a Fluorometer. 

Studies investigating hormonal activity revealed the oestrogenic activity of short-chain NPE in a number of test systems using either recombinant yeast, oestrogen-sensitive MCF-7 cells [98] or a rodent uterotrophic assay response. None of these assays have yet been validated as an internationally accepted toxicity test method, although the MCF-7 and uterotrophic assays have been established for a number of years as standard assays for oestrogenic activity. 

Breinholt, V. and J.C. Larsen. 1998. Detection of weak estrogenic flavanoids using a recombinant yeast strain and a modified MCF7 cell proliferation assay. Chem. Res. Toxicol. 11 622-629. 

Fig. 4. ATPase activity of Hsp90. (a) Titration of ATPase activity in purified recombinant yeast ffsp90 by addition of geldanamycin. ATPase activity was measured using a continuous enzyme-coupled assay, as previously described (Panaretou et al, 1998), which avoids end-product inhibition by ADP. (b) Hsp90 ATPase activity is stimulated at higher temperatures to a greater degree than expected, suggesting some mechanism of activation by heat shock.

Methanol and ethanol extracts of adenophora exhibited weak estrogenic effects in recombinant yeast system assays (Kang et al. 2006 Kim et al. 2008). 

Vanderperren, E. Demare, W. Blust, R. Cooreman, K. Bossier, P. Oestrogenic activity of CPRG (chlorophenol red- 3-D-galactopyranoside), a 3-galactosidase substrate commonly used in recombinant yeast oestrogenic assays. Biomarkers 2001, 6, 375-380. 

Assay for mitotic recombination in yeast and Drosophila Assay for unscheduled DNA synthesis in cultured hepatocytes and rodents... 

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