Proteomics

Defining RNA-binding protein preferences

RNA-binding preferences for only a few RNA-binding proteins (RBPs) have been determined, in part because existing methods are costly and laborious. Ray et al. describe a rapid approach, called RNAcompete, and use it to define RNA-binding specificities for nine RBPs. In this method, a diverse RNA pool is first generated; RNAs that bind to an RBP of interest are pulled down, fluorescently labeled and then analyzed via a microarray.

Ray, D. et al. Nat. Biotechnol. 27, 667–670 (2007).

Chemical biology

Quantum dot biosynthesis

Quantum dots are widely used in imaging applications. The synthetic methods used to make CdSe quantum dots, however, are anything but environmentally friendly. Seeking a more benign synthetic approach, Cui et al. now report a method to biosynthesize quantum dots in yeast cells. They do this by carefully controlling the timing and duration of the incubation of the yeast with Na2SeO3 and CdCl2 to generate CdSe quantum dots of various sizes with various fluorescence emission wavelengths.

Cui, R. et al. Adv. Funct. Mater. advance online publication (12 June 2009).

Genomics

Designing GWASs

Genome-wide association studies (GWASs) are very powerful methods for finding genetic variants that indicate risk for disease. Designing good GWASs, however, takes a lot of careful planning and usually a big budget. Spencer et al. describe a simulation method to assess the statistical power of different genotyping chips. Contrary to popular belief, they show that the chip with the highest coverage is not necessarily the best tool for the job.

Spencer, C.C.A. et al. PLoS Genet. 5, e1000477 (2009).

Biosensors

Detecting ozone

Although the stratospheric ozone layer crucially protects life on Earth from harmful ultraviolet rays, ground-level ozone is toxic. Garner et al. describe a small molecule–based, fluorescent turn-on probe for ozone, which can be used both as an atmospheric and a cell-based ozone sensor. This probe is highly selective for ozone and is not sensitive to the presence of other reactive oxygen species; it is a promising tool for better understanding the role of ozone in tissue damage.

Garner, A.L. et al. Nat. Chem. 1, 316–321 (2009).

Protein biochemistry

Enzymes for glycosphingolipid synthesis

Hancock et al. describe the generation of 'designer' enzymes for glycosphingolipid synthesis, using rational mutagenesis–based directed evolution and an enzyme-linked immunoassay (ELISA)–based screen to select glycosynthase mutants with improved catalytic activity. These enzymes could potentially be used to synthesize large quantities of pure glycosphingolipids for therapeutic applications.

Hancock, S.M et al. Nat. Chem. Biol. 5, 508–514 (2009).