A 100 kDa vanadate and lanzoprazole-sensitive ATPase from Streptococcus mutans membrane

Proteoliposomes in nanobiotechnology

“…Many of the so-called integral or transmembrane proteins completely cross the lipidic bilayer and, due to the strong hydrophobic interaction with the phospholipids, can only be removed with the use of detergents-tensoactive compounds which have the ability to decrease the lipid-lipid and lipidprotein interactions during the protein solubilization process (Gennis 1989;Le Maire et al 2000;Santos and Ciancaglini 2000;Santos et al 2002;Magalhães et al 2003;Schuck et al 2003;Heerklotz 2008). On the other hand, peripheral or extrinsic proteins have a superficial interaction with the polar heads of the membrane lipids and can be removed simply by a change in ionic strength or pH.…”

“…The removal of the different types of lipids is based on their solubilization in organic solvents (chloroform, methanol, acetone, among others) in which they are soluble, followed by their separation/characterization by analytical methods such as thin layer chromatography (Prasad 1996). The removal of the proteins from the isolated membranes is the more toilsome process, because proteins tend to lose their structures if removed from the membrane into an aqueous medium (Yeagle 1993;Gennis 1989;Rigaud et al 1995;Le Maire et al 2000;White et al 2001;Magalhães et al 2003;Seddon et al 2004;Kalipatnapu and Chattopadhyay 2005). These laborious procedures may be needed for complex, multimeric, multi-domain proteins, not easily obtainable in recombinant form, e.g.…”

-mercaptoethanol can reverse the inhibition of some glycolytic enzyme activities of Streptococcus mutans UA159 by benzimidazoles

“…Thø ba, chóng rÊt kh«ng bÒn trong dung dÞch axit; thêi gian ph©n hñy cña chóng chØ kho ¶ng 2 phót ë pH = 1,0 vµ kho ¶ng 20 phót ë pH = 7,4. Do ®ã, benzimidazon lµ mét tiÒn chÊt (prodrug), cã thÓ tËp trung t¹i bé phËn bÞ axit hãa cña tÕ bµo ®Ých vµ ë ®ã, nã sÏ ®−îc chuyÓn thµnh d¹ng ho¹t ®éng (active form) [7,9]. C¬ chÕ t¸c ®éng cña benzimidazon nãi chung x ¶y ra b¾t ®Çu b»ng viÖc ®−îc proton ho¸ ®Ó t¹o thµnh sunphenamit, mét d¹ng ho¹t ®éng.…”

Toluene permeabilization differentially affects F- and P-type ATPase activities present in the plasma membrane of Streptococcus mutans

“…Bacterial cells were stocked at -20°C in 40% glycerol (v/v) or in a candle jar for frequent utilization upon weekly subculturing on TSA. Large amounts of cells (about 1 g wet weight) were obtained from 1-liter cultures of complete medium incubated in a candle jar under magnetic stirring, as described by Magalhães et al (13), and grown until the pH reached 4.2. Growth curves were constructed by inoculating ~1 0 7 cells/mL of complete Toluene permeabilization of Streptococcus mutans www.bjournal.com.br medium (4 mL).…”

“…Acid tolerance by S. mutans has been studied in some detail, and it has been established that this microorganism possesses an inherent acid resistance that distinguishes it from other microorganisms not commonly associated with dental caries (8)(9)(10). This aciduricity has been largely attributed to the fact that S. mutans has both an F-type ATPase, which is expressed at higher levels in mutans streptococci plasma membrane and in many oral bacteria (11,12), and a Ptype ATPase, which was identified and characterized for the first time by Magalhães et al (13,14). Both membrane enzymes are responsible for cytoplasmic proton extrusion and regulation of the internal pH.…”