Background: The effects of specific collagen peptides on bone mineral density (BMD) in subjects with osteoporosis or osteopenia have already been investigated in 131 postmenopausal women in a randomized controlled trial. The purpose of this follow-up observation was to determine the longer-term effects of the same specific bioactive collagen peptides after a total intervention time of 4 years. Methods: In this open-label follow-up observation, 31 postmenopausal women with reduced BMD (initial T-score lower than−1 of either the femoral neck or the lumbar spine) completed the follow-up. BMD was measured via dual energy X-ray absorptiometry. Absolute changes in BMD and T-scores in the spine and femoral neck were assessed. The number of fractures was also recorded. All participants received specific bioactive collagen peptides. Results: Supplementation with bioactive collagen peptides during follow-up led to a clinically relevant increase in BMD in the spine. These findings were consistent with the results for the femoral neck. Conclusions Long-term supplementation with specific bioactive collagen peptides appears to be effective in counteracting losses in BMD. Moreover, significant increases in BMD could contribute to improved bone stability.

Background: The effects of specific collagen peptides on bone mineral density (BMD) in subjects with osteoporosis or osteopenia have already been investigated in 131 postmenopausal women in a randomized controlled trial. The purpose of this follow-up observation was to determine the longer-term effects of the same specific bioactive collagen peptides after a total intervention time of 4 years. Methods: In this open-label follow-up observation, 31 postmenopausal women with reduced BMD (initial T-score lower than−1 of either the femoral neck or the lumbar spine) completed the follow-up. BMD was measured via dual energy X-ray absorptiometry. Absolute changes in BMD and T-scores in the spine and femoral neck were assessed. The number of fractures was also recorded. All participants received specific bioactive collagen peptides. Results: Supplementation with bioactive collagen peptides during follow-up led to a clinically relevant increase in BMD in the spine. These findings were consistent with the results for the femoral neck. Conclusions Long-term supplementation with specific bioactive collagen peptides appears to be effective in counteracting losses in BMD. Moreover, significant increases in BMD could contribute to improved bone stability.

We here present a detailed study of the ligand-receptor interactions between single and triple-helical strands of collagen and the α2A domain of integrin (α2A), providing valuable new insights into the mechanisms and dynamics of collagen-integrin binding at a sub-molecular level. The occurrence of single and triple-helical strands of the collagen fragments was scrutinized with atom force microscopy (AFM) techniques. Strong interactions of the triple-stranded fragments comparable to those of collagen can only be detected for the 42mer triple-helical collagen-like peptide under study (which contains 42 amino acid residues per strand) by solid phase assays as well as by surface plasmon resonance (SPR) measurements. However, changes in NMR signals during titration and characteristic saturation transfer difference (STD) NMR signals are also detectable when α2A is added to a solution of the 21mer single-stranded collagen fragment. Molecular dynamics (MD) simulations employing different sets of force field parameters were applied to study the interaction between triple-helical or single-stranded collagen fragments with α2A. It is remarkable that even single-stranded collagen fragments can form various complexes with α2A showing significant differences in the complex stability with identical ligands. The results of MD simulations are in agreement with the signal alterations in our NMR experiments, which are indicative of the formation of weak complexes between single-stranded collagen and α2A in solution. These results provide useful information concerning possible interactions of α2A with small collagen fragments that are of relevance to the design of novel therapeutic A-domain inhibitors.
Animals ; Collagen ; chemistry ; metabolism ; Humans ; Integrins ; metabolism ; Magnetic Resonance Spectroscopy ; Molecular Dynamics Simulation ; Peptides ; chemistry ; metabolism ; Protein Binding ; Protein Structure, Tertiary ; Signal Transduction