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Antibacterial Films Made of Ionic Complexes of Poly(γ-glutamic acid) and Ethyl Lauroyl Arginate

by Ana Gamarra-Montes, Beatriz Missagia, Jordi Morató and Sebastián Muñoz-Guerra

Polymers 2018, 10(1), 21; https://doi.org/10.3390/polym10010021 - 24 Dec 2017

Cited by 18 | Viewed by 7069

The biocide agent LAE (ethyl ^αN-lauroyl l-arginate chloride) was coupled with poly(γ-glutamic acid) (PGGA) to form stable ionic complexes with LAE:PGGA ratios of 1 and 0.5. The nanostructure adopted by these complexes and its response to thermal changes were examined in detail by Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) using synchrotron radiation in real time. A layered biphasic structure with LAE filling the space between the polypeptidic sheets was adopted in these complexes. The complexes were stable up to above 250 °C, non-water soluble, and were able to form consistent transparent films. The release of LAE from the complexes upon incubation in aqueous buffer was examined and found to depend on both pH and complex composition. The antibacterial activity of films made of these complexes against Gram-positive (L. monocytogenes and S. aureus) and Gram-negative (E. coli and S. enterica) bacteria was preliminary evaluated and was found to be very high against the formers and only moderate against the later. The bactericide activity displayed by the LAE·PGGA complexes was directly related with the amount of LAE that was released from the film to the environment. Full article

(This article belongs to the Special Issue Host-Guest Polymer Complexes)

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Open AccessReview

Refolding Technology for scFv Using a New Detergent, N-Lauroyl-L-glutamate and Arginine

by Tsutomu Arakawa, Yoshiko Kita and Daisuke Ejima

Antibodies 2012, 1(2), 215-238; https://doi.org/10.3390/antib1020215 - 29 Aug 2012

Cited by 4 | Viewed by 10100

Abstract

Monoclonal antibodies to the soluble antigens or cell surface markers hold great promise as effective human therapeutics. One of the major disadvantages is its large size, which prevents efficient penetration into the target tissues. Smaller version of antibodies, which has only antigen binding sites, is extensively investigated. It becomes increasingly apparent, however, that these smaller fragments of antibodies are rather difficult to produce, as the normally efficient mammalian secretion system does not work well for these fragments. Thus, refolding of insoluble proteins produced in Escherichia coli is a method of choice, although such refolding is mainly based on trial-and-error experiment. Here we describe a novel refolding system using a new amino acid-based detergent, N-lauroyl-L-glutamate, and arginine. This detergent appears to readily dissociate from proteins below critical micelle concentration (CMC), while remaining effective in protein solubilization above CMC. Arginine suppresses protein aggregation when the detergent concentration was reduced below CMC. The interaction of the detergent and arginine with proteins, which play an important role in protein refolding, will be discussed in great length. Full article

(This article belongs to the Special Issue Monoclonal Antibody Preparation against Natural Product and Its Application)

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