Partial characterization of digestive proteases in sheepshead, Archosargus probatocephalus (Spariformes: Sparidae)

Abstract

Digestive proteases were partially characterized in sheepshead juveniles, using biochemical and electrophoretic techniques. Results showed higher activity level of the stomach proteases (2.39 ± 0.02 U mg protein-1) compared to the intestinal proteases (1.6 ± 0.1 U mg protein-1). The activity of trypsin, chymotrypsin, leucine aminopeptidase and carboxypeptidase A was also recorded. The optimum temperature of the stomach proteases was recorded at 45 °C, while for intestinal proteases was recorded at 55 °C. Stomach proteases showed less stability to temperature changes than intestinal proteases. An optimum pH of 2 was recorded for stomach proteases with high stability under acidic conditions, while an optimum pH of 9 was recorded for intestinal proteases showing high stability under alkaline conditions. Stomach proteases were inhibited around 78% with Pepstatin A, indicating the presence of pepsin as the main protease. The stomach proteases zymogam revealed one active band with Rf of 0.49, this enzyme was completely inhibited by Pepstatin A. The intestinal proteases zymogram revealed four active proteases (51.3, 34.9, 27.8 and 21.2 kDa) that were inhibited by TLCK, which mainly represent a trypsin-like serine proteases. It can be conclude that digestion in sheepshead can be considered as a carnivorous species with an omnivorous tendency.

Partial characterization of digestive proteases in Pacific red snapper Lutjanus peru Nichols & Murphy, 1922 (Perciformes: Lutjanidae)

“…Previous studies in L. gutattus showed pH pepsin optimum between 2 and 3, with two bands (Rf of 0.72 and 0.79) (Peña et al 2015(Peña et al , 2017. Some fish species shows a single pepsin band, such as C. undecimalis (Concha-Frías et al 2016) probatocephalus (Merino-Contreras et al 2018). Other species show pepsin isoforms such as European eel Anguilla anguilla (Linnaeus, 1758) with three isoforms (Wu et al 2009) and yellowfin seabream Acanthopagrus latus (Houttuyn, 1782) and mandarin fish Siniperca chuatsi (Basilewsky, 1855) that shows four pepsin isoforms (Zhou et al 2007(Zhou et al , 2008.…”

“…Therefore, studies concerning protein digestive physiology are necessary to develop a species-specific diet and determine the amount and type of ingredients that could be included. In this way, the appearance of digestive enzymes has been related to various physiological characteristics (feeding habits) and nutritional characteristics (requirements) in many species of marine fish, such as spotted rose snapper Lutjanus guttatus (Steindachner, 1869), thicklip grey mullet Chelon labrosus (Risso, 1827), common snook Centropomus undecimalis (Bloch, 1792) and sheepshead Archosargus probatocephalus (Walbaum, 1792) (Peña et al 2015, Concha-Frias et al 2016, Pujante et al 2017, Merino-Contreras et al 2018, as well as some freshwater fish, such as tropical gar Atractosteus tropicus Gill, 1863, Mayan cichlid Mayaheros urophthalmus (Günther, 1862), tree-spot cichlid Cichlasoma trimaculatum (Günther, 1867), green cichlid Cichlasoma beani (=Mayaheros beani) (Jordan, 1889) and short-tailed pipefish Microphis brachyurus (Bleeker, 1854) (Cuenca-Soria et al 2014, Toledo-Solís et al 2015, Martínez-Cárdenas et al 2020. Thus, the objective of the present work was to partially characterize the digestive proteases in the L. peru using biochemical and electrophoretic techniques.…”

Digestive Enzyme Activities in Barred Loach (Nemacheilus fasciatus, Val., 1846.): Effect of pH and Temperature

“…The presence of pepsin activity, which is active in acidic conditions was demonstrated in Horabagrus brachysoma and Bostrichthys sinensis (Renxie et al, 2010;Prasad and Suneesha, 2013), as well as Archosargus probatocephalus, which had pepsin with optimal activity at pH 2.0 (Merino-Contreras et al, 2018). Furthermore, a different condition was found in the posterior gut, which indicates the absence of pepsin-like activity.…”

Intestinal colonization against <i>Vibrio cholerae</i>: host and microbial resistance mechanisms

“…Moreover, a bacteriocin from Pediococcus acidilacticii QC38, also a gram-positive bacterium, was shown to have an antagonistic effect on V. cholerae . The study was carried out in vitro , and the culture supernatant of the bacterium used was isolated from a food product containing the bacterium [99] . These reports indicate that bacteriocins from gram-positive probiotics can effectively inhibit V. cholerae growth in vitro .…”