ArticlePharmaceutical research2007
Interplay of secondary structure and charge on the diffusion of a polypeptide through negatively charged aqueous pores.
Article in Pharmaceutical research, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
3 citing papers in PubMed, 17 citations in OpenAlex.
- Approaches for enhancing oral bioavailability of peptides and proteins.International journal of pharmaceutics · 2013Review
- A cyclosporin derivative discriminates between extracellular and intracellular cyclophilins.Angewandte Chemie (International ed. in English) · 2010Article
- Diffusion of anionic and neutral GFP derivatives through plasmodesmata in epidermal cells of Nicotiana benthamiana.Protoplasma · 2008Article
Corrections and comments
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Authors and funding
3 authors at 1 institution in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeThis study was conducted to investigate the interplay of secondary structure and charge of a polypeptide on its permeability through negatively charged pores of synthetic porous membranes and Caco-2 cell monolayers. MATERIALS AND
methodsPoly(D-glutamic acid) [Poly(D-Glu)] was used as a model polypeptide. Transport studies were conducted at 37 degrees C through both track-etched polycarbonate membranes (using side-by-side diffusion cells) and Caco-2 cell monolayers. Apparent permeability coefficients and diffusion coefficients were calculated.
resultsWhen diffusion was unhindered, poly(D-Glu) appeared to be transported at the same rate regardless of whether it existed in the random coil or the alpha-helix secondary structure. When moderately hindered diffusion was evaluated, poly(D-Glu) with partial alpha-helix secondary structure, exhibited significantly greater transport than when the polypeptide predominantly existed as the highly negatively charged random coil. This trend was reversed when the diffusion was severely hindered by the tight junctions of the Caco-2 cell monolayers.
conclusionsNeither charge, nor secondary structure, played a significant role in the unhindered diffusion of poly(D-Glu). When the molecules were moderately hindered, polypeptide/membrane charge interactions significantly influenced the rate of aqueous diffusion. As the overall molecular dimensions of the polypeptide approached the pore size, the inherent molecular flexibility of the random coil secondary structure overcame the effect of charge repulsion.
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Registered trials
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