Quantification of calpastatin using an optical surface plasmon resonance biosensor

Area of Science:

• Food Science
• Biotechnology
• Analytical Chemistry

Background:

• Calpastatin is a key protein influencing meat tenderness.
• Accurate and efficient methods for calpastatin measurement are needed in the meat industry.
• Existing methods for calpastatin activity assay are labor-intensive.

Purpose of the Study:

• To develop and validate an immunological biosensor for calpastatin detection.
• To assess the relationship between biosensor measurements and calpastatin activity.
• To investigate the correlation between early postmortem calpastatin levels and meat tenderness.

Main Methods:

• Development of a surface plasmon resonance (SPR) based biosensor system (Biacore Q).
• Assay validation using ovine and bovine muscle and heart extracts.
• Correlation analysis of biosensor data with enzymatic calpastatin activity measurements.
• Investigation of postmortem calpastatin degradation and its relation to shear force in bovine longissimus dorsi.

Main Results:

• The calpastatin biosensor demonstrated a linear relationship with calpastatin activity (R²=0.51–0.99).
• High assay precision was achieved with intra- and inter-assay coefficients of variation <6%.
• Immunologically detectable calpastatin decreased faster than inhibitory activity postmortem, suggesting epitope degradation.
• Calpastatin content at 1 day postmortem significantly correlated with shear force at 14 days postmortem (r=0.75).

Conclusions:

• The developed SPR biosensor is a reliable tool for quantifying calpastatin in meat samples.
• The biosensor assay shows potential for at-line determination of calpastatin in beef processing plants.
• Current applications are suitable for research, breed evaluation, and selection programs due to reduced labor compared to traditional methods.