Snakehead Fish, Channa striata (Bloch, 1973), Protein Concentrate: Excellent Recovery of Fish-Based Albumin Source and Its Possible Application for Sperm Capacitation

Abstract

Snakehead fish protein concentrate (SFC) shows promising recovery of excellent protein content that has broad potential applications, including the future use of its albumin content as a sperm capacitation promoter. However, the quantity of snakehead fish albumin recovered depends on several variables, including the habitat in which the fish thrives, extraction procedures, and the assay employed. To optimise the albumin content retrieved from snakehead fish flesh with more reliable results, multiple protein extraction methods were undertaken through the protein concentrate preparation and analysed using the Bromocresol purple (BCP) albumin assay. Total soluble protein (TSP), albumin level, and albumin proportion were recovered at a significant reduction in an acid solvent when exposed to up to 50 °C heating compared to extractions undertaken without heating. Moreover, the small number of protein bands identified indicates that the combination of acid solvent and heating treatment was similarly damaging. In this study, we detected the presence of albumin in SFC at 32 %, the highest percentage ever recorded employing the BCP assay, following extraction with water solvent without thermal treatment. Using SDS-PAGE and densitometric analysis, the identified putative albumin-related bands from the two major bands at 40 kDa and 47 kDa, containing respective proportions of 57 % and 16 % of the total protein loaded. Although this exploratory work requires additional analysis and purification steps, further research employing the SFC is worth identifying its ability and how this alternative albumin source can replace serum albumin to modulate the capacitation process in mammalian sperm.