# Efficient expression and purification of rat CRP in Pichia pastoris

## TL;DR

This paper presents an efficient method to express and purify rat C-reactive protein using the Pichia pastoris system.

## Contribution

The study introduces an optimized recombinant expression and purification strategy for rat CRP in Pichia pastoris.

## Key findings

- Recombinant rat CRP was efficiently expressed and purified using the Pichia pastoris system.
- The new method outperforms traditional purification techniques in terms of efficiency and effectiveness.
- The optimized approach enables high-quality production of rat CRP for further structural and functional studies.

## Abstract

C-reactive protein (CRP) plays a crucial role in the diagnosis and monitoring of the non-specific acute phase response in humans. In contrast, rat CRP (rCRP) is an atypical acute-phase protein that possesses unique features, such as a possible incapacity to trigger the complement system and markedly elevated baseline plasma concentrations. To facilitate in vitro studies on these unique characteristics, obtaining high-quality pure rCRP is essential. Here we explored various strategies for rCRP purification, including direct isolation from rat plasma and recombinant expression in both prokaryotic and eukaryotic systems. Our study optimized the recombinant expression system to enhance the secretion and purification efficiency of rCRP. Compared to traditional purification methods, we present a streamlined and effective approach for the expression and purification of rCRP in the Pichia pastoris system. This refined methodology offers significant improvements in the efficiency and effectiveness of rCRP purification, thereby facilitating further structural and functional studies on rCRP.