An engineered protein tag for multiprotein labeling in living cells.

The visualization of complex cellular processes involving multiple proteins requires the use of spectroscopically distinguishable fluorescent reporters. We have previously introduced the SNAP-tag as a general tool for the specific labeling of SNAP-tag fusion proteins in living cells. The SNAP-tag is derived from the human DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) and can be covalently labeled in living cells using O6-benzylguanine derivatives bearing a chemical probe.

Indoloquinolizidine derivatives as novel and potent apoptosis inducers and cell-cycle blockers.

A collection of approximately 11 000 natural-product derived and inspired compounds was screened for potential apoptosis inducers in the human tumour cell lines HepG2 (liver), HeLa (cervix) and MCF-7 (breast) by means of MTT and ATP-luminescence assays, automated cell counting, caspase 3/7 assay as well as by fluorescence activated cell sorting (FACS) analysis. A group of seven indoloquinolizidine derivatives was identified that exhibited IC(50) values for cell proliferation as low as 2 mumol L(-1), with no major necrosis of cells detectable. At the same time, an increase in the rate of apoptosis of up to 600 % relative to the reference level was observed.

Discovery of protein phosphatase inhibitor classes by biology-oriented synthesis.

Protein phosphatases have very recently emerged as important targets for chemical biology and medicinal chemistry research, and new phosphatase inhibitor classes are in high demand. The underlying frameworks of natural products represent the evolutionarily selected fractions of chemical space explored by nature so far and meet the criteria of relevance to nature and biological prevalidation most crucial to inhibitor development. We refer to synthesis efforts and compound collection development based on these criteria as biology-oriented synthesis.