Kinetics of Protein Precipitation: optimizing recovery, purity, and throughput…

Kinetics of Protein Precipitation: optimizing recovery, purity, and throughput using the ProTrap XG

Jessica L. Nickerson¹ , Alan A. Doucette¹

¹Dalhousie University, Halifax, NS, Canada

Introduction

Efficient sample preparation is key to any proteomics workflow, with three priorities at the forefront: protein recovery, purity, and sample throughput. Acetone precipitation is a common method of purifying proteins from a complex sample prior to LC-MS/MS analysis, but is sometimes set aside due to seemingly variable yields.¹ Our group previously established that the addition of 1-30 mM salt with 80% v/v acetone facilitates recoveries >95%.² We later developed a filtration cartridge (ProTrap XG) which automates precipitation and SDS depletion.³ In order to maximize recovery, purity and sample throughput, we investigated the kinetics of protein precipitation with respect to structural properties of proteins, including molecular weight, hydrophobicity, and charge.