Enzyme Activities inSchistosoma mansoniSoluble Egg Antigen

Abstract

Schistosoma mansoni egg antigens are mostly responsible for the granulomatous pathology in human intestinal schistosomiasis. Several previous studies have indicated that the induction of an immune response against some parasite enzymes may protect against pathology. The present work was designed to identify enzyme activities present in a standard soluble egg antigen (SEA) preparation. Simple colorimetric analyses were performed incubating SEA with 2-naphthyl, 2-naphthylamide (2NA), or p-nitrophenyl substrates at different pHs in the absence of added effectors. Results showed prominent acid phosphatase (pH 5.4), alkaline phosphatase (pH 8.5), and N-acetyl-beta-glucosaminidase (pH 5.4) activities. Relevant peptidase activities were also detected at pH 6.5-7.5 against 2NA derivatives of (1) aliphatic (alpha-Ala > beta-Ala > Leu > Met > S-benzyl-Cys), polar (Ser > Gln), basic (Arg > Lys > ornithine), and acidic (Glu) amino acids; (2) dipeptides: X-Ala (X = Gly > Leu > Lys > Asp), X-Arg (X = Ala > Arg > Phe > Gly > Pro > Asp), Ser-Met, and Phe-Pro; and (3) tripeptides (Ala-Phe-Pro > Phe-Pro-Ala). The data demonstrated that S. mansoni SEA contains a rich set of hydrolases with different specificities that might play a role in the egg physiology and possibly also in the host-parasite relationships.

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“…In the case of the female schistosome, several glycosidases were found more abundantly secreted, including beta-glucosidase (Smp_043390, A0A3Q0KF32_SCHMA), alpha-galactosidase (Smp_089290, G4VLE3_SCHMA), and several alpha-amylases. Furthermore, it has been suggested that hydrolases released by the schistosome egg contribute to the transit of the egg and the circumoval granuloma across the intestinal wall and also with the nutritional requirements of the embryo (Cesari et al, 2000). Despite our findings, we cannot rule out that hydrolases detected here could have been secreted by eggs when released by females in vitro and may not originate from the adult female.…”

Comparative real-time PCR and enzyme analysis of selected gender-associated molecules inSchistosoma japonicum

“…1986; Fan et al . 2002) and S. mansoni (Cesari et al . 2000), the arginase enzyme has not been studied in schistosomes in any detail.…”

In vitroeffect of schistosomicidal drugs on hepatic arylsulfatase B from theSchistosoma-infected mouse

“…However, a change in various enzymes was observed during Schistasoma mansoni such as arylsulfatase B [9] and many hydrolases [10][11][12][13]. Arylsulfatases A, B and C (arylsulfo-hydrolases) are a group of hydrolytic enzymes that occur in various tissues and fluids [14].…”