Antioxidative Activity of Soy, Wheat and Pea Protein Isolates Characterized by Multi-Enzyme Hydrolysis

Hydrolysis of protein by proteases produces small molecular weights (MWs) peptides as nanomaterials that are easily absorbed. This study investigated the physicochemical properties and antioxidant activity of three plant protein isolates (PIs) including soy, wheat and pea after multi-enzyme hydrolysis. The MWs, particle size and microstructure of PI hydrolysate (PIH) were determined by SDS-PAGE and MALDI-TOF-MS mass spectrometry, dynamic light scattering and transmission electron microscopy, respectively. Cell viability was determined in vitro using a mouse skeletal muscle cell line (C2C12) and crystal violet staining. The MWs and particle sizes of the three plant PIs were reduced after hydrolysis by three proteases (bromelain, Neutrase and Flavourzyme). The MWs of soy, wheat and pea PIH were 103.5–383.0 Da, 103.5–1146.5 Da and 103.1–1937.7 Da, respectively, and particle size distributions of 1.9–2.0 nm, 3.2–5.6 nm and 1.3–3.2 nm, respectively. All three plant PIHs appeared as aggregated nanoparticles. Soy PIH (100 μg/mL) provided better protection against H2O2-induced oxidative damage to C2C12 than wheat or pea PIH. In summary, soy PIH had the best antioxidant activity, and particle size than wheat PIH and pea PIH. Therefore, soy PIH might be a dietary supplement for healthy diet and medical applications.

Structure based analysis of KATP channel with a DEND syndrome mutation in murine skeletal muscle

Developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome, the most severe end of neonatal diabetes mellitus, is caused by mutation in the ATP-sensitive potassium (KATP) channel. In addition to diabetes, DEND patients present muscle weakness as one of the symptoms, and although the muscle weakness is considered to originate in the brain, the pathological effects of mutated KATP channels in skeletal muscle remain elusive. Here, we describe the local effects of the KATP channel on muscle by expressing the mutation present in the KATP channels of the DEND syndrome in the murine skeletal muscle cell line C2C12 in combination with computer simulation. The present study revealed that the DEND mutation can lead to a hyperpolarized state of the muscle cell membrane, and molecular dynamics simulations based on a recently reported high-resolution structure provide an explanation as to why the mutation reduces ATP sensitivity and reveal the changes in the local interactions between ATP molecules and the channel.

Establishment of a human skeletal muscle-derived cell line: biochemical, cellular and electrophysiological characterization

We characterized excitation–contraction coupling of an immortalized human skeletal muscle cell line and show the potential application of this cell line as a platform for the screaning of drugs to treating defects caused by mutations in genes involved in Ca2+ regulation.