Cat. # FTZ01

Product uses

• Identification and characterization of FtsZ binding proteins
• Characterization of FtsZ dynamics
• Developing FtsZ ligands that may be used as anti-bacterial agents.
  
  

Material
FtsZ is a bacterial cytoskeletal protein that is essential for cell division many prokaryotes (1).  It has been shown to be a bacterial homolog of eukaryotic tubulin, based both on a low sequence identity and a striking structural similarity (2).  Just like eukaryotic tubulin, FtsZ polymerizes as well as binds and hydrolyzes GTP in a polymerization dependent manner.

Cytoskeleton, Inc's FtsZ protein has been expressed in E. coli and purified by DEAE cellulose chromatography as described by Lu and coworkers (3).  It is active in both polymerization and GTPase assays.  FtsZ has an approximate molecular weight of 50 kDa.

Purity
Protein purity is determined by scanning densitometry of Coomassie Blue stained protein on a 10% polyacrylamide gel.  FtsZ protein was found to be >75% pure (see Figure 1). The major contaminants are E.coli proteins that co-purify with FtsZ.  These contaminants may result in a slightly higher GTPase activity.

Figure 1: A 20 µg sample of FTZ01 was separated on a 10% SDS-PAGE gel. The protein was stained with Coomassie Blue. Protein quantitation was performed with the Precision Red Advanced Protein Assay Reagent (Cat. # ADV02).

Biological activity
The biological activity of FtsZ is determined in two ways, first from its ability to efficiently polymerize into filaments in vitro in the presence of Ca²⁺ and GTP, and secondly to readily hydrolyze GTP to GDP and P_i.  Polymerization by Ca²⁺:GTP results in bundles of FtsZ filaments that sediment at 50,000 x g.  GTPase activity is determined by measuring the Pi released during a 5min reaction, by using the malachite green reagent (Cat. # BK050). In these reactions, more than 70% of our FtsZ protein polymerizes and it has a GTPase activity above 0.3 mol GTP/mol FtsZ/min.

References

1. Bramhill, D. (1997) Bacterial cell division. Annu. Rev. Cell Dev. Biol. 13, 395-424.
2. Erickson, H. P. (1998) Atomic structures of tubulin and FtsZ. Trends Cell Biol. 8, 133-137.
3. Lu, C., Stricker, J., and Erickson, H. P. (2001) Site-specific mutations of FtsZ--effects on GTPase and in vitro assembly. BMC Microbiol. 1, 7.