Enhanced Cellular Uptake of Antisecretory Peptide AF-16 through Proteoglycan Binding
Journal article, 2014

Peptide AF-16, which includes the active site of Antisecretory Factor protein, has antisecretory and antiinflammatory properties, making it a potent drug candidate for treatment of secretory and inflammatory diseases such as diarrhea, inflammatory bowel diseases, and intracranial hypertension. Despite remarkable physiological effects and great pharmaceutical need for drug discovery, very little is yet understood about AF-16 mechanism of action. In order to address interaction mechanisms, we investigated the binding of AF-16 to sulfated glycosaminoglycan, heparin, with focus on the effect of pH and ionic strength, and studied the influence of cell-surface proteoglycans on cellular uptake efficiency. Confocal laser scanning microscopy and flow cytometry experiments on wild type and proteoglycan-deficient Chinese hamster ovary cells reveal an endocytotic nature of AF-16 cellular uptake that is, however, less efficient for the cells lacking cell-surface proteoglycans. Isothermal titration calorimetry provides quantitative thermodynamic data and evidence for that the peptide affinity to heparin increases at lower pH and ionic strength. Experimental data, supported by theoretical modeling, of peptide−glycosaminoglycan interaction indicate that it has a large electrostatic contribution, which will be enhanced in diseases accompanied by decreased pH and ionic strength. These observations show that cell-surface proteoglycans are of general and crucial importance for the antisecretory and anti-inflammatory activities of AF-16.

Antisecretory Factor

Peptide

AF-16

Isothermal Titration Calorimetry

Heparin

Cellular Uptake

Flow Cytometry

Confocal Microscopy

Proteoglycans

Author

Maria Matson Dzebo

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Anna Reymer

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Kristina Fant

SP Sveriges Tekniska Forskningsinstitut AB

Per Lincoln

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Bengt Nordén

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Sandra Rocha

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Biochemistry

0006-2960 (ISSN) 1520-4995 (eISSN)

Vol. 53 41 6566-6573

Subject Categories

Physical Chemistry

Roots

Basic sciences

Areas of Advance

Life Science Engineering

DOI

10.1021/bi5010377

PubMed

25289567

More information

Latest update

9/6/2018 1