Interaction of Mycoplasma gallisepticum with sialyl glycoproteins

Abstract

The binding of several glycoproteins to freshly grown and harvested cells of Mycoplasma gallisepticum was examined. Only human glycophorin, the major sialoglycoprotein of the erythrocyte membrane, bound tightly as judged by direct binding assays with 125I-labeled glycoproteins. Neuraminidase-treated glycophorin did not bind, suggesting that binding is mediated through sialic acid groups. Although other sialoglycoproteins did not appear to bind M. gallisepticum by direct binding assays, some inhibited the binding of glycophorin. The best inhibitors had a mucin-like structure, with high molecular weights and high sialic acid contents. N-acetylneuraminic acid appeared to be the favored sialic acid structure for binding, but there was no strict specificity for its anomeric linkage. Neuraminidase activity could not be detected on the surface of M. gallisepticum, suggesting that this enzyme is not involved in the mechanism of adherence of sialoglycoproteins. Binding of sialoglycoproteins was time dependent, however, and markedly diminished with increasing ionic strength, but was largely unaffected between pH 4 and 9.

New Insights into the Host–Pathogen Interaction of Mycoplasma gallisepticum and Avian Metapneumovirus in Tracheal Organ Cultures of Chicken

“…The movement (gliding) is accomplished by a postulated catch-pull-release cycle [60], which may be very vulnerable to interferences during the binding process [59]. A similar pattern can be assumed for M. gallispeticum since Glasgow et al, found that M. gallispeticum also interacts with sialyl glycoproteins to mediate attachment [61], and similar proteins required to initiate the infection process were found [58].…”

A survey of avian Mycoplasma species for neuraminidase enzymatic activity

“…This was found also for cultures of the S6 strain which is widely used as M. gallisepticum antigen in serology. The fact that some S6 cultures had very low NEAC might be the explanation why Glasgow and Hill (1980) did not detect NEAC in the S6 strain. On the other hand, our results confirm suggestion that M. gallisepticum exhibits neuraminidase activity (Sethi and Müller, 1972).…”

“…However, data about the neuraminidase enzymatic activity (NEAC) in different M. gallisepticum strains are conflicting (Roberts, 1967;Sethi and Müller, 1972;Glasgow and Hill, 1980). Indeed, it has been reported that A c c e p t e d M a n u s c r i p t 4 reference strains of M. gallisepticum, S6 and A5969, did not reveal detectable neuraminidase activity (Glasgow and Hill, 1980;Kahane et al, 1990). Both, M. gallisepticum and M. synoviae bind to host cell via receptors containing sialic acid residues (Razin, 1985).…”