Surfactin

Surfactin Bacterial lipopeptide biosurfactant inhibits clot formation (387)... 

Magetdana, R. and Ptak, M. (1995). Interactions of surfactin with membrane models, Biophys. J., 68, 1937-1943. 

In linear NRPSs a product consisting of amino acids is biosynthesized in an N- to C-terminal manner by the multidomain assembly line with a domain organization of A-PCP-(C-A-PCP) i-TE. The initiation module of a linear NRPS lacks a C domain, while the following modules may include any required additional domains. After formation of the full-length peptide, the product is released from the assembly line by a termination domain. Thus, the number and order of amino acids in the peptide directly coincides with the number and order of synthetase modules. Many NRPs are biosynthesized in this manner, and characterized examples include the penicillin tripeptide precursor -(L-0 -aminoadipyl)-L-cysteinyl-D-valine (ACV, Figure 4 (a)), complestatin, cyclosporin, fengycin, surfactin, and tyrocidine. "... 

Figure 11 Structurai representatives of the core NRPS domains from X-ray crystallographic analysis, (a) Two conformations (brown box) of A domains differing in the orientation of the subdomains. The top structure (PDB code, 1 AMU) is postuiated to be the conformation responsible for activating the amino acid and the lower (PDB code, 3CW9) for loading the amino acid onto the phosphopantetheine arm. (b) X-ray structure of the VibH condensation domain (PDB code, 1L5A) and (c) the TE domain from surfactin synthetase (PDB code, 1JMK) are also illustrated in ribbon format.

The termination module of surfactin synthetase is a 144 kDa four-domain enzyme responsible for the incorporation of the final amino acid (L-Leu) into the surfactin peptide and subsequent cyclization of the resulting product. The structure of the TE domain of this construct was previously solved. In the recently determined 2.6 A X-ray structure of the C-A-PCP-TE construct, the entire protein chain is evident in the electron density maps. " " The structural folds of the individual domains in this module are similar to structures of monomeric domains (Figure 13). The deviations observed in this multidomain structure include a slight difference in the hinge region of C domain subdomains and an orientation of the subdomains of the A domain that is not consistent with the open or closed conformations previously described. The A domain contains... 

Figure 13 X-ray structure of the four-domain termination moduie of surfactin synthetase (PDB code, 2VSQ). The coioring and representation of the domains is the same as in Figures 11 and 12. A cartoon diagram of the reiative domain structure is iiiustrated at the right of the two views. Ac and An signify the C-terminai and N-terminai subdomains of the A domain.

The PKS TE from erythromycin biosynthesis and the NRPS TE from surfactin biosynthesis are remarkably similar in three-dimensional topology (Figure 7.3) [42, 43]. It is expected that the application of enzyme-directed evolution will be able to further broaden the synthehc applications of TEs by increasing their activity and stability [44]. 

Kalinovskaya. N.I. Kuznetsova, T.A. Rashkes, Ya.V. Mil grom, Yu.M. Mil grom, E.G. et al. (1995) Surfactin-like structures of five cyclic depsipeptides from the marine isolate of Bacillus pumilus. Russ. Chem. Bull., 44, 951-5. 

Noah, K. S., Fox, S. L., Bruhn, D. F., Thompson, D. N., Bala, G. A. (2002). Development of continuous surfactin production from potato process effluent by Bacillus subtilis in an airlift reactor. Appl. Biochem. BiotechnoL, 99(1-3), 803-814. 

Takahashi, T., Ohno, O., Ikeda, Y., Sawa, R., Homma, Y., Igarashi, M., and Umezawa, K. (2006). Inhibition of lipopolysaccharide activity by a bacterial cyclic lipopeptide surfactin. ]. Antibiot. 59, 35-43. 

Arima, K., Kakinuma, A. Tamura, G. (1968). Surfactin, a crystalline peptidolipid surfactant produced by Bacillus subtilis isolation, characterization and its inhibition of fibrin clot formation. Biochemical and Biophysical Research Communication, 31, 488-94. 

Figure 8.23 Left XPS survey spectrum recorded on palladium. Right Nitrogen IS spectrum of a surfactin/DPPC monolayer on mica. The vertical scale shows the number of counts per second. Adapted from ref. [358],...

Wagner B, Sieber SA, Baumann M et al (2006) Solvent engineering substantially enhances the chemoenzymatic production of surfactin. ChemBioChem 7 595-597... 

The replacement of product amino acid residues by positional alteration of domains [102,103], The cysteine- and valine-specific activa-tion-thiolation didomains of P. chrysogenum ACV synthetase have been successfully inserted into the terminal position of surfactin synthetase in Bacillus subtilis [102], In the case of ACV synthetase, e.g., specific domains could be replaced to generate new tripeptides or to improve the efficiency of poorly incorporated amino acid analogues. 

The alteration of product structures by domain repositioning. The terminal thioesterase domain of surfactin synthetase has been repositioned to obtain acyl-tetra- and pentapeptide fragments in vivo of the cycloheptapeptidolactone [104], In the case of ACV synthetase, repositioning of the thioesterase domain would be expected to lead to dipeptides of the AC type. If this specific thioesterase would only release peptides of the D-configuration, alternative thioesterases from other NRPS systems might work. 

The separation of domains to obtain interacting systems with multiple components. This approach directs efforts to enzymatic combinatorial approaches and permits selective improvements on single domains [85], The thioesterase domain of surfactin synthetase has been separately expressed in a thioesterase-deleted surfactin synthetase system and shown to be functional [105], Thus, specific protein-protein inter-... 

PH Weinreb, LE Quadri, CT Walsh, P Zuber. Stoichiometry and specificity of in vitro phosphopantetheinylation and aminoacylation of the valine-activating module of surfactin synthetase. Biochemistry 37 1575-1584, 1998. 

E Guenzi, G Galli, I Grgurina, E Pace, P Ferranti, G Grandi. Coordinate transcription and physical linkage of domains in surfactin synthetase are not essential for proper assembly and activity of the multienzyme complex. J Biol Chem 273 14403-14410, 1998. 

K Kim, SY Jung, DK Lee, JK Jung, JK Park, DK Kim, CH Lee. Suppression of inflammatory responses by surfactin, a selective inhibitor of platelet cytosolic phospholipase A2. Biochem Pharmacol 55 975-985, 1998. 

Dimitrov, K., Gancel, F., Montastruc, L. and Nikov, I. (2008) Liquid membrane extraction of bio-active amphiphilic substances Recovery of surfactin. Biochemical Engineering Journal, 42, 248. 

Characterization of Surfactin from Bacillus subtilis for Application as an Agent for Enhanced Oil Recovery... 

Index Entries Bacillus subtilis biosurfactant surfactin improved oil recovery oil recovery agent. 

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