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Updated: May 15, 2026

Assays for Studying the Role of Vitronectin in Bacterial Adhesion and Serum Resistance
Published on: October 16, 2018
Recombinant N-terminal Fragment of Human Vitronectin Promotes Osteoblast Adhesive Responses via αvβ3 and αvβ5
O Bok Kim1, Sung Youn Jung1, Byung-Moo Min1
1Department of Oral Biochemistry and Program in Cancer and Developmental Biology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Korea.
Abstract:
Vitronectin is a key extracellular matrix glycoprotein, but the functional contribution of specific residues within its N-terminal region to osteoblast activity remains poorly defined. We engineered a recombinant N-terminal fragment of human vitronectin (rVn-FI; residues 20-149) and performed a comprehensive mapping study using 16 overlapping 12-mer peptides to pinpoint the exact bioactive motifs. rVn-FI significantly promoted adhesion, spreading, and migration in HOS and MG-63 osteoblast-like cells, mediated primarily by αvβ3 and αvβ5 integrins. Peptide mapping revealed that two RGD-containing motifs-Vn-FI-P6 (AECKPQVTRGDV) and Vn-FI-P7 (PQVTRGDVFTMP)-were the sole drivers of this activity. Notably, Vn-FI-P7 exhibited a significantly higher inhibitory potency against cell adhesion to vitronectin than Vn-FI-P6, suggesting that the flanking sequences in Vn-FI-P7 provide a superior conformational context for integrin binding. None of the other 14 peptides showed biological activity, confirming the absence of non-RGD-dependent binding sites within the N-terminal fragment (residues 20-149). These results define the precise functional boundaries of the vitronectin N-terminus for osteoblast interaction. Our findings highlight that the flanking sequences in Vn-FI-P7 provide a superior conformational context for RGD-integrin binding, offering specific peptide targets for enhancing the bioactivity of bone tissue engineering scaffolds.
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