Improved solid-phase DNA probe method for tRNA purification: large-scale preparation and alteration of DNA fixation

Area of Science:

• Biochemistry
• Molecular Biology
• Biotechnology

Background:

• Solid-phase DNA probe hybridization is standard for transfer RNA (tRNA) purification.
• High melting temperatures of thermophilic tRNAs challenge conventional purification methods.
• Previous studies utilized tetraalkylammonium salts to improve purification of thermostable tRNAs.

Purpose of the Study:

• To develop an improved, large-scale purification system for thermophilic tRNAs.
• To address the rapid column deterioration observed with biotinylated DNA probes.
• To create a more economical and reusable tRNA purification method.

Main Methods:

• A large-scale purification system was established using tetraalkylammonium salts.
• A covalent DNA fixation method was developed using N-hydroxysuccinimide-activated agarose and a 5'-aminohexyl (dT)8 oligomer.
• In-column probe sequence synthesis was performed using Klenow enzyme.

Main Results:

• The novel method increased tRNA yield by over 10-fold compared to previous procedures.
• Manual steps were significantly reduced.
• The covalently fixed DNA probe allowed for repeated column use and washing with warmed buffers, enhancing durability and cost-effectiveness.

Conclusions:

• Covalent DNA fixation offers a robust and economical solution for purifying thermostable tRNAs.
• This method overcomes the limitations of shedding biotinylated probes, enabling repeated use and improved efficiency.
• The developed system facilitates large-scale purification of challenging thermophilic tRNA samples.