Abstract
Earlier peptidomic analysis of the skin secretion of Xenopus amieti led to the identification of orthologs of magainins and other peptides. This study investigated the degradation, in vitro insulin-releasing and acute metabolic effects of magainin-AM1 (GIKEFAHSLGKFG KAFVGGILNQ) and magainin-AM2 (GVSKILHSAGKFGKAFLGEIMKS). Plasma degradation was investigated using reversed-phase HPLC and MALDI-TOF mass spectroscopy. Insulin-releasing effects were determined using BRIN-BD11 clonal beta cells and mouse islets. Effects of magainin peptides on cytosolic enzyme lactate dehydrogenase release, membrane potential and intracellular Ca(2+) concentration were assessed using BRIN-BD11 cells while their in vivo effects on glucose tolerance and insulin release were assessed in obese, insulin-resistant Swiss National Institute of Health (NIH) mice. Both peptides were resistant to degradation by plasma enzymes in vitro for up to 8 h. Though magainin-AM1 elicited non-toxic, concentration-dependent stimulation of insulin-release from clonal BRINBD11 cells at concentrations ≥ 100nM, magainin-AM2 produced a higher stimulation of insulin-release from BRIN-BD11 cells and isolated mouse islets. Membrane depolarization and intracellular [Ca(2+)]i in BRIN-BD11 cells were significantly (P
| Original language | English |
|---|---|
| Pages (from-to) | 256-263 |
| Journal | Protein and Peptide Letters |
| Volume | 22 |
| Issue number | 3 |
| Publication status | Published (in print/issue) - 1 Feb 2014 |
Keywords
- Cytokine
- Toxicity
- 1.1B4
- Insulin secretion
