Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.4.99.6 (sialyltransferase)
 1,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gonococci (strain BS4(agar)), emerging from lag-phase during 1-1.5 h incubation in a medium containing glucose (28 mM) and either 5 microM or 50 microM sodium lactate, show enhanced capacity for their lipopolysaccharide (LPS) to be sialylated by cytidine 5'-monophospho-N-acetyl neuraminic acid. The sialyltransferase content of the lactate-treated gonococci was not greater than that of control organisms and showed no differences in LPS components. However, the total LPS content of the lactate-treated gonococci was 10-20% higher than that of control organisms, so lactate enhancement may be due to more sialyl receptors becoming available due to an overall stimulation of LPS synthesis. The protein and pentose contents of the lactate-treated gonococci were also higher than those of controls, indicating stimulation of protein synthesis and ribosome production. Electron microscopy showed hair-like external appendages on control but not on lactate-treated gonococci. The above growth conditions are unnatural. However, when concentrations of glucose and lactate were adjusted to values akin to those occurring in vivo (glucose 5 mM alone and with either 1 mM or 10 mM lactate), and gonococcal multiplication occurred during the short incubation period (1-1.5 h), lactate again induced greater contents of LPS, protein and pentose. A high content of LPS, which will contribute to pathogenicity, should be a constant feature of gonococci growing in human urogenital tissues, where lactate is ever present with glucose.
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PMID:Lactate causes changes in gonococci including increased lipopolysaccharide synthesis during short-term incubation in media containing glucose. 986 75

Promotion of uptake of essential metabolites is a possible reason for the general stimulation of gonococcal metabolism which is caused by lactate (1 mM) in a defined medium containing glucose (5 mM). However, although uptake of(14)C adenine by gonococci [strain BS4(agar)] held for 4 or 7 min at 37 degrees C in Hanks balanced salt solution was increased for lactate treated gonococci compared with control organisms, uptake of(14)C glucose and(14)C proline under these conditions was unaffected. Hence, there is no evidence that lactate produces general stimulation of metabolite uptake. Unlike the other metabolites, cytidine 5'-monophospho-(14)CN-acetyl neuraminic acid (CMP-(14)CNANA), the substrate for sialylation of gonococcal lipopolysaccharide (LPS), was adsorbed in substantial quantities by gonococci held on ice for 6 min. Also, the increase in uptake of CMP-(14)CNANA at 37 degrees C over that adsorbed at 0 degrees C was much smaller (less than two-fold) than for the other compounds (4-30-fold). The substantial adsorption at 0 degrees C suggested a surface receptor for CMP-(14)CNANA. It is probably the sialyltransferase because a sialyltransferase deficient mutant, JB1, did not absorb CMP-(14)CNANA at 0 degrees C or take it up at 37 degrees C, in contrast to its parent strain, F62, which behaved similarly to strain BS4 (agar). This supports previous evidence for a surface location of the sialyltransferase. There was a small increase in adsorption of CMP-(14)CNANA in lactate treated gonococci indicating a slight increase in the surface enzyme. This could enhance LPS sialylation and hence affect pathogenicity.
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PMID:Uptake of metabolites by gonococci grown with lactate in a medium containing glucose: evidence for a surface location of the sialyltransferase. 1079 76