TY - JOUR T1 - Stabilizing effect of knots on proteins. JF - Proceedings of the National Academy of Sciences of the United States of America Y1 - 2008 A1 - Joanna I. Sulkowska A1 - Sulkowski, Piotr A1 - Szymczak, P A1 - Cieplak, Marek KW - Computer Simulation KW - Disulfides KW - Hot Temperature KW - Humans KW - Models, Chemical KW - Ornithine Carbamoyltransferase KW - Protein Folding KW - Protein Structure, Secondary KW - Stress, Mechanical AB - Molecular dynamics studies within a coarse-grained, structure-based model were used on two similar proteins belonging to the transcarbamylase family to probe the effects of the knot in the native structure of a protein. The first protein, N-acetylornithine transcarbamylase, contains no knot, whereas human ormithine transcarbamylase contains a trefoil knot located deep within the sequence. In addition, we also analyzed a modified transferase with the knot removed by the appropriate change of a knot-making crossing of the protein chain. The studies of thermally and mechanically induced unfolding processes suggest a larger intrinsic stability of the protein with the knot. VL - 105 IS - 50 ER -