Activity of proteolytic enzymes in the intestine of bream Abramis brama infected with cestodes Caryophyllaeus laticeps (Cestoda, Caryophyllidea)

Surviving in the fish gut: Comparative inhibitory capacities against the host proteinases in cestodes of the genus Proteocephalus

“…In the Proteocephalus tapeworms studied here, the incubation media and extracts contained protein bands with comparable apparent molecular weights ranging from 12 to 35 kDa. Similarly, the presence of common protein bands with apparent molecular weights of 19–47 kDa in the incubation medium and the tapeworm extracts was shown for another cestode Caryophyllaeus laticeps from the bream intestine, along with the ability of these substances to inhibit the proteinase activity (Frolova et al., 2019). Meanwhile, in Triaenophorus nodulosus tapeworms from the intestines of pike, inhibitory capacity was related to the protein fraction with an apparent molecular weight of 14.4 kDa (Rogozhin et al., 2019).…”

“…The proteins with similar molecular masses (from 15 to 250 kDa) were also found in the excretory-secretory products of the Hymenolepis diminuta cestode infecting mammalian hosts(Bień et al, 2016).In the Proteocephalus tapeworms studied here, the incubation media and extracts contained protein bands with comparable apparent molecular weights ranging from 12 to 35 kDa. Similarly, the presence of common protein bands with apparent molecular weights of 19-47 kDa in the incubation medium and the tapeworm extracts was shown for another cestode Caryophyllaeus laticeps from the bream intestine, along with the ability of these substances to inhibit the proteinase activity(Frolova et al, 2019). Meanwhile, inF I G U R E 6 Relative width of the protein bands (%) detected on the electrophoregrams of the incubation media (a) and extracts (b) from various Proteocephalus tapeworms.…”

“…Currently, the nature and performance of the inhibitory substances enabling the helminths to resist attacks of host proteolytic enzymes are still poorly understood, especially regarding the tapeworms inhabiting the fish gut. The worm homogenates and their incubation medium were found to inhibit host proteinases and commercial trypsin samples in such tapeworms as Triaenophorus nodulosus from the pike Esox lucius (Izvekova et al., 2017a; Rogozhin et al., 2019), Eubothrium rugosum from the burbot Lota lota (Izvekova et al., 2017b) and Caryophyllaeus laticeps from the bream Abramis brama (Frolova et al., 2019). However, it should be noted that these studies were performed only with disparate host–parasite pairs, making it difficult to compare the results and establish the presence and degree of interspecific variability in the inhibitory capacities of the worms.…”

“…Helminths hardly induce obvious pathogenic effects in their hosts at a low-grade invasion that prevails in the wild (Mitchell, 1993), and some parasites, especially small-sized ones, are often overlooked by non-parasitologists. Many physiologists are prone to studying helminth-free fish, considering them to be closer to a physiological norm (Frolova et al, 2019), though the parasites are now recognized as part and parcel of any ecosystem (Strona, 2015). That is why the complex host-parasite relationships should be involved when exploring the digestive processes.Despite the impressive progress in studying the genome and proteome of helminths, many aspects of the host-parasite interaction…”

Localization of the proteinase inhibitor activity in the fish cestode Eubothrium rugosum

“…As known, the activity of enzymes operating in the digestive tract of vertebrates, including fish, is influenced by a variety of biotic and abiotic factors. Among them is infection with parasites, including cestodes (Frolova et al, 2019;Izvekova & Solovyev, 2016). Of great importance for understanding the nature of parasitism is knowledge of the mechanisms whereby parasites affect nutrient utilization by the hosts.…”