Isolation and characterization of paramyosin from abalone (Haliotis discus hannai)

In order to investigate the characterization of paramyosin (PM), PM was purified from the muscle of abalone (Haliotis discus hannai) by ammonium sulfate fractionation and hydroxyapatite chromatography. The molecular mass of PM was about 97.0 ku as estimated by SDS-PAGE. Peptide mass fingerprinting of PM obtained 36 peptide fragments with a total of 403 amino acid residues, which were 99.7% and 72.0% identical with PMs from H. discus discus and Crassostres gigas, respectively. The isoelectric point of PM detected by two-dimensional electrophoresis was approximately 5.4, suggesting it is an acidic protein. Circular dichroism spectrum of PM solution demonstrated a rotatory maximum at 192 nm and two negative peaks at 208 nm and 223 nm, indicating the typical spectral characteristic of α-helix structure. Meanwhile, the denaturation temperature (T_d) of PM was 58.1 °C as determined by circular dichroism spectrum analysis. FTIR spectra further confirmed that PM has intact α-helical structure. The isolation and physicochemical property investigation of PM from the muscle of abalone would provide theoretical foundation for studying proteins related to its texture and for deep-processing of abalone products.