Abstract

The biochemical basis for the incidence of pale, soft, exudative (PSE) turkey meat was investigated by conducting ryanodine binding experiments on sarcoplasmic reticulum (SR) vesicles prepared from genetically unimproved and commercial turkeys. Ryanodine binding to the Ca2+ channel protein in SR vesicles from both populations of turkeys was activated at a threshold concentration of approximately 0.2 microM Ca2+, reached a plateau over the range of 3 to 30 microM free Ca2+, and was only slightly inhibited at 1 mM Ca2+. The SR fractions, enriched in the Ca(2+)-channel protein, from commercial turkeys exhibited a higher (P < 0.05) mean affinity for ryanodine when compared to that from unimproved turkeys (Kd = 12.2 vs 20.5 nM, respectively). A fourfold difference (P < 0.05) in mean Ca(2+)-channel protein content or Bmax (1.10 pmol/mg vs 4.01 pmol/mg) was observed between commercial and unimproved turkey SR fractions. The apparent difference in channel protein content between the two populations may be partially accounted for by the high abundance of a 75-kDa protein, as yet unidentified, observed in most commercial turkey samples on SDS polyacrylamide gels. The differences in ryanodine binding activity between these two populations of turkeys suggest that altered SR calcium channel protein activity, or altered channel regulation, may be associated with the increased incidence of PSE meat from turkeys selected for growth characteristics.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.