Immobilization ofEscherichia coliCells by Use of the Antimicrobial Peptide Cecropin P1

Abstract

An immobilization scheme for bacterial cells is described, in which the antimicrobial peptide cecropin P1 was used to trap Escherichia coli K-12 and O157:H7 cells on microtiter plate well surfaces. Cecropin P1 was covalently attached to the well surfaces, and E. coli cells were allowed to bind to the peptide-coated surface. The immobilized cells were detected colorimetrically with an anti-E. coli antibody-horseradish peroxidase conjugate. Binding curves were obtained in which the signal intensities were dependent upon the cell concentration and upon the amount of peptide attached to the well surface. After normalization for the amount of peptide coupled to the surface and the relative binding affinity of the antibody for each strain, the binding data were compared, which indicated that there was a strong preference for E. coli O157:H7 over E. coli K-12. The cells could be immobilized reproducibly at pH values ranging from 5 to 10 and at ionic strengths up to 0.50 M.

Synthesis of Bioinorganic Antimicrobial Peptide Nanoparticles with Potential Therapeutic Properties

“…In models proposing the antimicrobial mechanism of cationic peptides (e.g., toroidial pore and barrel-stave), a conformationally free form of the peptide is required for insertion and orientation across membrane barriers. 52 While surface-immobilized AMPs have shown to bind to cell surfaces and reduce viability, 53,54 it is likely a fraction of the encapsulated peptide diffused from the particles and this free form of the peptide contributed to the biocidal effect in the assays.…”

Methods for Whole Cell Detection of Microorganisms

“…With this in mind, several researchers have exploited the selective binding properties of naturally-occurring AMPs for use in bacterial capture or immobilization (84,85,95). For example, Kulagina et al (85) used magainin I as a capture reagent for a proof-of-concept silanized glass array detector targeting Salmonella and E. coli 0157:H7.…”

“…As fully synthetic compounds, such reagents may also have the added advantages of relatively simple and scalable production and the ability to incorporate surface-binding chemistries, facilitating their attachment to sensor surfaces. Apart from detection, the use of AMPs to selectively bind bacteria and even discriminate pathogenic and non-pathogenic cell types may also be very useful in such wide-ranging applications as cell-based immobilized bed reactors for industrial fermentations, water purification and bioremediation of con taminated materials (84).…”

“…Several approaches to the development of antibody-like (and therefore biomimetic) binders have also been described in recent years. These include bioimprinted sol-gel polymers for binding whole yeast cells (83), peptide-based binders (84,85,86) and "affibodies" -non-antibody binders derived from randomizable small protein scaffolds (e.g. staphylococcal protein A) (87,88).…”

Estudo da relação estrutura-atividades e de propriedades do Hb40-61a, uma hemocidina sintética

“…Além disso, a exploração da relação estrutura-atividade e o entendimento dos seus mecanismos de ação podem levar a análogos e compostos novos com propriedades mais interessantes do que os compostos de partida ) ou à descoberta de outras ações, tais a como inibição de enzimas, promoção de absorção cutânea para administração tópica de fármacos, imobilização de células com diferentes afinidades sobre superfícies sólidas ou, ainda, incorporação à embalagem de alimentos (GREGORY; MELLO, 2005, MILTZ et al, 2006, KIM et al, 2007.…”