The protein kinases of rat liver nuclei

Two compounds with properties of Factor F-430 were purified from $\text{Methanobacterium}\text{bryantii}$ by column chromatography. Analysis of these compounds by neutron activation and atomic absorption spectroscopy revealed the presence of nickel and the absence of other metals commonly associated with molecules of biological origin. For the two compounds, the masses are 3300 daltons per mol Ni and 1500 daltons per mol Ni. The absorbance at 430 nm of both compounds is between 2.7?2.1 × 10⁴ cm^?1 L (mol Ni)^?1. Factor F-430 appears to be a unique, nickel-containing compound of low molecular weight.