High efficiency method to obtain supercoiled DNA with a commercial plasmid purification kit.

Supercoiled state corresponds to the active form for plasmid applications. The relaxed circular form of plasmids is often inactive or poorly active. To obtain significant amounts of almost fully supercoiled DNA, we modified the standard protocol of a commercially available Qiagen plasmid purification kit.

A sperm nuclear basic protein from the sperm of the marine worm Chaetopterus variopedatus with sequence similarity to the arginine-rich C-termini of chordate protamine-likes.

The sperm nuclear basic proteins (SNBPs) of the marine annelid worm Chaetopterus variopedatus have been shown previously to consist of a mixture of two SNBPs: histone H1-like (CvH1) and C.variopedatus protamine-like (CvPL). Here, we report the structural characterization of CvPL.