background: the most reliable indicator of vitamin d status is circulating concentration of 25‑hydroxycalciferol (25(oh) d) routinely determined by enzyme‑immunoassays (eia) methods. this study was performed to compare commonly used competitive protein‑binding assays (cpba)‑based eia with the gold standard, high‑pressure liquid chromatography (hplc). methods: concentrations of 25(oh) d in sera ...

1. A competitive protein-binding assay for plasma 25-hydroxycholecalciferol was developed, using Sephadex LH-20 columns for the isolation of the sterol and a partially purified protein from rat serum as the binding protein. 2. The mean plasma 25-hydroxycholecalciferol in eighteen male and female normal volunteers was 38 5 SD 14 pmol/ml (1 5.2 & 5.6 nglml). 3. Levels of 25-hydroxycholecalciferol...

The protein folding problem is a fundamental problem in computational molecular biology and biochemical physics which led us to understand the function of a given sequence.The problem is NP-hard and the standard computational approach are not suitable to obtain the enough accurate structure in the huge conformation space. Simplied models such as hydrophobicpolar (HP) model have become one of th...