Schistosome proteolytic enzyme

Grant, Carlos; Senft, Alfred W.

doi:10.1016/0305-0491(71)90269-0

Cited by 14 publications

(3 citation statements)

References 16 publications

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“…Finally, it is the separation of labour among sexually dimorphic individuals which probably represents one of the most important evolutionary advantages obtained through the acquisition of dioeciousness. Separation of labour allows the female schistosome to direct all of her genetic and metabolic machinery to maximize reproductive fitness and become a highly efficient egg-laying machine (Sturrock, 1966 ;Grant, 1971). The male schistosome ensures the survival of females (and of the species) by providing physical transportation within the vasculature (Basch, 1991), musculature to aid feeding (Gupta & Basch, 1987 ;Basch, 1990), and other chemo-or thigmaticmaturation factors (Robinson, 1960 ;Popiel & Basch, 1984) as well as providing sperm to fertilize the oocyte (which may not be necessary in some species ).…”

Section: B I O L O G Y O F T H E D I O E C I O U S S T a T Ementioning

confidence: 99%

An historical and genomic view of schistosome conjugal biology with emphasis on sex-specific gene expression

Hoffmann

2004

Parasitology

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The genetic programmes associated with the sexual biology of dioecious schistosomes remain a critically important but significantly understudied area of parasitology. Throughout the last four decades, progress has been slow in describing the gross antigenic and proteomic differences linked to sexually mature schistosomes and in characterizing some of the sex-associated transcripts and regulatory mechanisms induced during developmental maturation. These investigations have been severely hindered by the lack of complete EST/genomic information, as well as corresponding post- and functional-genomic tools for studying these pathogenic parasites. As near complete transcriptomes for Schistosoma japonicum and S. mansoni have recently been reported, and both DNA microarrays and post-transcriptional gene silencing have been applied to schistosomes, the tools and techniques for the high-throughput identification and characterization of transcripts involved in conjugal biology are now readily available. Here, an historical review is presented that summarizes some of the most significant findings associated with schistosome sex and sexual maturation during the last several decades. Following this discussion is a current overview of some modern day genomic approaches used to study schistosomes, which illustrates how major advances in the field of conjugal biology will be achieved.

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Section: B I O L O G Y O F T H E D I O E C I O U S S T a T Ementioning

confidence: 99%

An historical and genomic view of schistosome conjugal biology with emphasis on sex-specific gene expression

Hoffmann

2004

Parasitology

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“…The proteinase had an acidic pH optimum (Grant and Senft, 1971) and a molecular mass of 27 (Sauer and Senft, 1972) or of 32 kDa (Deelder et al, 1977). It hydrolysed haemoglobin, but not other natural blood proteins, which led to the suggestion that the proteinase was responsible for haemoglobin degradation in the schistosome digestive tract (Timms and Bueding, 1959).…”

Section: Introductionmentioning

confidence: 99%

Expression and partial characterization of a cathepsin B-like enzyme (Sm31) and a proposed ‘haemoglobinase’ (Sm32) from Schistosoma mansoni

Götz¹,

Klinkert²

1993

Biochemical Journal

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Schistosoma mansoni protein Sm31 is a cysteine proteinase similar to mammalian lysosomal cathepsin B, proposed to be a key enzyme in schistosome metabolism. Protein Sm32 has been identified as a putative cysteine proteinase termed a ‘haemoglobinase’. Since neither Sm31 nor Sm32 have been completely purified, some controversy of the nature of the ‘true’ digestive enzyme still exists. By incubating a radiolabelled cysteine-proteinase active-site-directed synthetic inhibitor with total S. mansoni proteins, the target of inhibition was Sm31 and not Sm32. The selectivity and irreversibility of inactivation make affinity labelling an invaluable tool for exploring key differences among closely related enzymes and also for studying proteinase activity in a cellular environment. In order to confirm these results, we expressed the complete cDNA sequences of Sm31 and Sm32 in insect cells and analysed the recombinant gene products for proteolytic activities. Cell extracts containing S. mansoni cathepsin B, but not those expressing ‘haemoglobinase’, were demonstrated to cleave a synthetic substrate benzyloxycarbonyl-arginylarginylaminomethylcoumarin in fluorescence assays. Our findings confirm previous assertions that a cysteine proteinase resembling cathepsin B is the haemoglobinase involved in digestion of host proteins. Thus, the original proposal that Sm32 is a cysteine proteinase has not been verified, and its function remains unknown.

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“…This result was taken as evidence that this protease is able to degrade human hemoglobin very specifically and effectively and was subsequently termed hemoglobinase. Cathepsin B is not inhibited by phenylalanine (not shown), a property attributed to the hemoglobinolytic activity analyzed by Senft and co-workers (50,51), and does not show a preference toward hemoglobin. Therefore, cathepsin B does not merit the term hemoglobinase and most likely is not identical with these early reports of hemoglobinolytic activity.…”

Section: Discussionmentioning

confidence: 74%

Cathepsin B of Schistosoma mansoni

Lipps

Füllkrug

Beck

1996

Journal of Biological Chemistry

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Procathepsin B from the parasitic trematode Schistosoma mansoni was expressed as a glycosylation-minus mutant in yeast cells and purified by means of a histidine affinity tag which was added to the carboxyl terminus of the recombinant protein. The purified zymogen underwent autoprocessing but required an assisting protease for activation. Pepsin-activated schistosomal cathepsin B was further characterized with the cathepsin B-specific substrates N-benzyloxycarbonyl (Z)-Arg-Arg-p-nitroanilide, Z-Arg-Arg-7-amido-4-methylcoumarin, and Z-Phe-Arg-7-amido-4-methylcoumarin. A proteolytic activity comparable to mammalian cathepsin B was observed. In addition, we analyzed the degradation of human hemoglobin by schistosomal cathepsin B, which has been suggested to be the physiological target of the protease.

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Schistosome proteolytic enzyme

Cited by 14 publications

References 16 publications

An historical and genomic view of schistosome conjugal biology with emphasis on sex-specific gene expression

An historical and genomic view of schistosome conjugal biology with emphasis on sex-specific gene expression

Expression and partial characterization of a cathepsin B-like enzyme (Sm31) and a proposed ‘haemoglobinase’ (Sm32) from Schistosoma mansoni

Cathepsin B of Schistosoma mansoni

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