Sialidases occurrence

Monitoring of the levels of total sialic acid and lipid-associated sialic acid in serum is an important diagnostic tool for the detection of precancerous lesions [224], Transition-state analogues derived from sialic acid are potent inhibitors of sialidases from various influenza virus strains, and these have been evaluated clinically as influenza remedies [225], A detailed review of our current knowledge regarding the occurrence, specificity and function of sialic acid-specific lectins, particularly those that occur in viruses, bacteria and non-vertebrate eukaryotes has been recently published [226],... 

E. Medina-Acosta, S. Paul, S. Tomlinson, and L. C. Pontes-de-Carvalho, Combined occurrence of trypanosomal sialidase/trans-sialidase activities and leishmanial metalloproteinase gene homologues in Endotrypanum sp, Mol. Biochem. Parasitol, 64 (1994) 273-282. 

Abstract In contrast to the general hydrolases, trans-sialidase from Trypanosoma cruzi (TcTS) shows excellent regio- and stereoselectivity as well as high yields in transfer reactions. Discussed are the occurrence of trans-sialidases and studies on the transfer mechanism. In detail, the preparative use by chemoenzymatic syntheses with TcTS are outlined with emphasis on the design of modified donor and acceptor substrates. Another section focuses on attempts to develop inhibitors for TcTS, and these endeavors are based on donor- and acceptor-inspired modifications as well as on some completely different structures. 

Fiorilli, A., Siniscalco, C., Chiarini, A., di Francesco, L., Venerando, B., and Tettamanti, G., 1991, Occurrence of sialidase activity in two distinct and highly homogeneous populations of lysosomes prepared from the brain of developing mouse, FEBS Lett. 282 235-238. 

In 1960, the occurrence of mammalian sialidase was reported by Warren and Spearing. Shortly thereafter, Ada and Lind (1961) found sialidase in the chorioallantoic membrane of the embryonic chicken, and Carubelli et aL (1962) found sialidase in several organs of the rat. Much work since has been done on microbial and on mammalian sialidases, and to a lesser degree, on avian sialidase, to determine intracellular and organellar locations of the enzyme, and its properties and biological functions. 

In the microbial world, occurrence of sialidase appears mostly to be restricted to ortho- and to paramyxoviruses and to members of two major taxonomic orders of bacteria, Eubacteriales and Pseudomona-dales (for review, Drzeniek, 1972), but not entirely. Sialidase also has been uncovered in one of the Mycoplasmatales (gallisepticum, Sethi and Muller, 1972 Roberts, 1967), as well as in a structurally related L-phase variant of Vibrio comma, or cholerae (Madoff et aL, 1961) this latter belongs, however, to the Spirillaceae family of the aforementioned Pseudomonadales. Sialidase has been found also in a higher Protistan, Trichomonas foetus (Romanovska and Watkins, 1963) and in several strains of a fungus, Streptomyces albus (Myhill and Cook, 1972), of the order Actinomycetales. Future discoveries may further widen the pat-... 

---