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Gracilaria changii is a red seaweed species in Malaysia with high protein content (12.57% (dry basis)). Thus, G. changii proteins are potential precursors for producing bioactive peptides. To date, no study has been reported on the potential of G. changii proteins as potential precursors for bioactive peptides. In this study, fourteen G. changii proteins were selected as potential precursors of bioactive peptides using in silico approach. It was found that the most potential bioactivity was dipeptidyl peptidase-IV (DPP IV) inhibitory and angiotensin-I converting enzyme (ACE) inhibitory activities. Papain, ficin and stem bromelain were used for in-silico proteolysis. Stem bromelain was found to be more effective in terms of the release of fragments with a given activity. Furthermore, two tripeptides (ACF and YCL) were screened as novel and promising bioactive peptides. The characteristics of both peptides were also analyzed using PeptideRanker, PepCalc, Peptide Cutter, ToxinPred, AllerTop and AHTpin bioinformatic tools. The bioinformatic tools predicted that both peptides were non-toxic, non-allergen and highly potential. The present work suggests that G. changii can serve as a potential source of bioactive peptides and these findings can provide a basis for future in-vitro and in-vivo study of bioactive peptides from G. changii proteins.

This study aimed to optimize the enzymatic hydrolysis conditions of Gracilaria fisheri protein by using Alcalase® to obtain maximum angiotensin-I-converting enzyme (ACE) inhibitory activity. Firstly, the seaweed protein was extracted using cellulase, sonication, and ammonium sulphate treatment, before dialysis and lyophilization. The yield of lyophilized seaweed protein extract was 8.75% with a protein content of 66.4%. An optimization study for protein hydrolysis condition was performed by employing a three-level face-centered central composite design (CCD) using Design-Expert software. Four parameters used were pH (6.5 – 8.5), temperature (50 – 60°C), hydrolysis time (60 – 180 min), and Alcalase® to substrate ratio (E/S) (1.25 – 2.50%). Thirty runs of protein hydrolysis conditions with 6 center points were employed. The supernatant of the resulting protein hydrolysates was then lyophilized and analyzed for ACE inhibitory activity. This study found that the quadratic model could be used to explain the relationship between hydrolysis conditions of G. fisheri protein and ACE inhibitory activity. The optimum condition to obtain maximum ACE inhibitory activity was at pH of 7.5, the temperature of 54.6°C, hydrolysis time of 175 min, and E/S of 1.47%. The half-maximal inhibitory concentration (IC50) of the seaweed protein hydrolysate at optimum condition was 2.97 ± 0.37 mg/mL.

Background: Multisite LV stimulation therapy allows for stimulation of two different left ventricular pacing vectors within a single LV lead and may improve responsiveness to cardiac resynchronization therapy (CRT). This study prospectively evaluated the safety and efficacy of the MultiPole Pacing (MPP) feature in CRT non-responder patients. Methods and Results: CRT non-responders with a standard CRT-D indication were eligible for enrollment into the MPP Sub-Study. Patient status, NYHA classification, Patient Global Assessment (PGA), and adverse events were collected at follow-up. A clinical composite score (CCS) was determined at the 6 month follow-up visit. The primary objective was defined as the proportion of patients with an improved CCS. Safetywas evaluated as freedom from MPP system related adverse events requiring additional invasive intervention to resolve. A total of 53 patients were enrolled across 26 U.S. centers. The cumulative follow-up duration was 24.1 years. CCS was improved in 35.6% of patients (p < .0001 when compared to a performance goal of 3%) after 6 months of MPP therapy. When incorporating patient feedback into a modified CCS, 60.0% of patients showed an improvement. Three patients (5.7%) experienced hospitalization for heart failure, and three patient deaths occurred over the follow-up period. No MPP system-related events were reported for an AE-free rate of 100% (95% CI 93.28% to 100.0%). Conclusions:The results of this small, non-randomized study suggest that the MPP feature is safe, and may be effective at converting a percentage of CRT non-responders to responders. Larger, randomized studies are needed to confirm this result.