Separation technique for messenger RNAs by use of schizophyllan/poly(A) tail complexation

Schizophyllan (SPG) is one of the water soluble beta-1,3-glucans and has a peculiar molecular recognition capability, namely, the single stranded SPG (s-SPG) can form a stoichiometric complex with certain polynucleotides such as poly(C) and poly(A), although it cannot bind poly(G) and poly(dC) at all. In this paper, we prepared an s-SPG-appended column and made an attempt to separate polynucleotides on the bases of this molecular recognition capability. The s-SPG-appended column trapped only such RNAs that could form the complex with s-SPG but eluted other RNAs which did not form the complex. Encouraged by the results in the model system, we extended the s-SPG-appended column into separation of native messenger RNAs (mRNAs) from a RNA mixture (total RNA) obtained from yeast. Since eukaryotic mRNAs have a poly(A) tail with 150-300 bases, we supposed that the tails would be trapped by the s-SPG-appended column. The results indicate that mRNAs were separated from total RNA in good yield and with high purity. It should be emphasized that this is the first device to separate natural mRNAs without using a dA/dT Watson-Crick-type interaction.