# Revealing the global mechanism related to carnosine synthesis in the pectoralis major of slow-growing Korat chickens using a proteomic approach

## TL;DR

This study uses proteomics to uncover how carnosine levels differ in the breast muscle of slow-growing Korat chickens, revealing mechanisms related to muscle function and meat quality.

## Contribution

This is the first detailed proteomic analysis of global mechanisms underlying carnosine synthesis in meat with divergent concentrations.

## Key findings

- Eight proteins were differentially expressed between low- and high-carnosine groups, linked to endoplasmic reticulum pathways.
- High carnosine levels correlate with specific protein abundances that support muscle homeostasis and meat quality.
- Carnosine synthesis appears to aid muscle recovery and function after disruption of its precursors.

## Abstract

This study aimed to find global mechanisms related to carnosine synthesis in slow-growing Korat chickens (KRC) using a proteomic approach.

M. pectoralis major samples were collected from 10-week-old female KRC including low-carnosine (LC, 2,756.6±82.88 μg/g; n = 5) and high-carnosine (HC, 4,212.5 ±82.88 μg/g; n = 5).

We identified 152 common proteins, and 8 of these proteins showed differential expression between the LC and HC groups (p<0.05). Heat shock 70 kDa protein 8, Heat shock 70 kDa protein 2, protein disulfide isomerase family A, member 6, and endoplasmic reticulum resident protein 29 were significantly involved in protein processing in the endoplasmic reticulum pathway (false discovery rate<0.05), suggesting that the pathway is related to differential carnosine concentration in the M. pectoralis major of KRC. A high concentration of carnosine in the meat is mainly involved in low abundances of Titin isoform Ch12 and Connectin and high abundances of M-protein to maintain homeostasis during muscle contraction. These consequences improve meat characteristics, which were confirmed by the principal component analysis.

Carnosine synthesis may occur when muscle cells need to recover homeostasis after being interfered with carnosine synthesis precursors, leading to improved muscle function. To the best of our knowledge, this is the first study to describe in detail the global molecular mechanisms in divergent carnosine contents in meat based on the proteomic approach.