Cell adhesive peptide screening of the mouse laminin α1 chain G domain.

Cell adhesive peptides have been widely applied for therapeutic drugs, drug delivery systems, and biomaterials. Previously, we identified various cell adhesive sequences in the G domains of four laminin α chains (α2-α5) by the systematic soluble peptide screening. We also identified five cell-binding sequences in the laminin α1 chain G domain using synthetic peptide-polystyrene beads. Here, we re-screened cell adhesive peptides in the laminin α1 chain G domain by the systematic soluble peptides screening. The 110 soluble peptides were evaluated for their cell adhesive activities using human fibrosarcoma HT1080 cells and human dermal fibroblasts. Fourteen peptides were newly identified as a cell adhesive. Additionally, four peptides (AG22: SSFHFDGSGYAM, AG42: TFDLLRNSYGVRK, AG76: HQNQMDYATLQLQ, AG86: LGGLPSHYRARNI) promoted integrin-mediated cell adhesion. Further, neurite outgrowth activity with rat pheochromocytoma PC12 cells was evaluated and two peptides (AG20: SIGLWNYIEREGK, AG26: SPNGLLFYLASNG) were newly identified for neurite outgrowth activity. These results suggested that the systematic soluble peptides screening approach is an accurate and powerful strategy for finding biologically active sequences. The active sequences newly identified here could be involved in the biological functions of this domain. The active peptides are useful for evaluating molecular mechanisms of laminin-receptor interactions and for developing cell adhesive biomaterials.

The influence of synthetic peptides derived from the laminin alpha1 chain on hepatocyte adhesion and gene expression.

Laminin-111, a heterotrimer composed of the laminin alpha1, beta1, and gamma1 chains, has been used as a biomaterial for primary cell culture to maintain cellular functions. Our previous studies have reported that synthetic peptides derived from laminin alpha1 exhibit biological functions such as influencing cell adhesion, migration, angiogenesis, and tumor metastasis. In this study we screened hepatocyte attachment peptides using twenty-five biologically active peptides from laminin alpha1 and examined the maintenance of hepatic function on the peptides using primary rat hepatocytes. Peptide A13 (RQVFQVAYIIIKA), mouse laminin alpha1 chain residues 121-133, exhibited the strongest activity. Furthermore, primary hepatocytes on A13 peptide maintained expression of hepatic differentiation markers such as tyrosine aminotransferase, tryptophan-2,3-dioxygenase, and cytochrome P450. We also determined the active core sequence of A13 using systematically truncated N- and C-terminal peptides. The results indicated that the nine-amino acid sequence RQVFQVAYI was critical for A13's hepatocyte adhesion activity. However, the truncated peptides could not interact with beta1-intgerin and maintain expression of hepatic differentiation markers. The amino acid sequence of A13 peptide was required for regulating hepatocyte behavior. The hepatocyte adhesive peptides can be utilized in tailoring synthetic biomaterials in order to achieve a specific cellular response.