Part:BBa_K5185003

Human integrins α1 domain（α1）

The integrin α1 domain (α1) is part of the integrin α1β1 complex, a cell surface receptor involved in cell adhesion, motility, and signal transduction. This domain is responsible for binding to extracellular matrix (ECM) proteins, particularly collagen. By studying and potentially modifying the α1 domain, we can influence cell ECM interactions relevant to tissue engineering and therapeutic interventions.

Other than α1, this part collection includes α2 and CBMs. This part collection of CBMs aimed to provide first aid wound dressings with enhanced antimicrobial functions and a wider and more complex application, where we characterize bacterial cellulose modification methods and constructs using CBMs as a binding domain, linking HNPs such as HNP1 and HNP4 to carbohydrates such as cellulose and chitosan. By incorporating α1 into proteins, collagen-containing materials can be effective targets for modification or degradation. The part collection includes: Cellulose binding matrices CBM2 (BBa_K4011001) which binds to trehalose, CBM3 (BBa_K4011000) which binds to fibrin, CBM5 (BBa_K5185002) which binds to chitosan, and VbCBMxx (BBa_K5185008) which binds to sodium alginate. Human integrins α1 domain (BBa_K5185003) and α2 domain (BBa_K5185004), linking functional proteins to collagen. This part collection can help to achieve modification of cellulose membranes using different modification/functionalization proteins.

Since collagen in itself promotes new skin cell growth, it could be targeted for use in wound dressings that prioritize wound recovery.

Usage and Biology

In the human body, the integrin α1 domain mediates cell adhesion to collagen types I and IV, playing essential roles in tissue remodeling, wound healing, and angiogenesis. This domain contains a metal-ion-dependent adhesion site (MIDAS) crucial for ligand binding. The α1 domain also participates in intracellular signaling pathways that regulate cell proliferation, differentiation, and survival. The structure of the integrin α1 domain is available in the Protein Data Bank (accession: 1PT6). Research involving the α1 domain includes exploring its role in treating medical conditions such as fibrosis, cancer, and inflammatory conditions, making it a target for therapeutic development.

Source

The integrin α1 domain is derived from human cells expressing the integrin α1β1 complex.

Results

We obtained a fusion protein composed of a binding domain protein linked to a fluorescent protein, naming it α1-mRFP. Figure A shows the results of the SDS-PAGE analysis of the target fusion proteins (binding domains linked to chromoproteins). The α1-mRFP fusion protein was expressed in E. coli BL21 (DE3). α1-mRFP has a molecular weight of 49.2kDa and is successfully expressed. The color of α1-mRFP suspended in 20mM Tris-HCl under bluelight is shown in Figure B, expressing the correct color red. α1's ability to bind with collagen is assessed, as shown in Figure C. It is important to note that the α1 binding domain is intended to interact specifically with type IV collagen. However, due to budget constraints in our lab, we assessed its binding ability using type II collagen instead. The comparatively lower brightness observed in the sodium alginate and collagen mixture after washing may be ascribed to this restraint. Nevertheless, the results indicate that our α1-mRFP fusion protein can successfully bind to the collagen material, as it remains brighter than the control group.

Figure 1:

Figure 1:
(a) SDS-PAGE identification of BDC shows the results of SDS-PAGE analysis of the target fusion proteins(BDC). All fusion proteins were expressed in E. coli BL21 (DE3), except for CBMxx-gfasPurple, which was expressed in the SHuffle T7 strain due to its low solubility in BL21 (DE3). α1-mRFP, α2-eforRed, CBM2-mTurquoise, CBM3-sfGFP, CBM5-fwYellow, and CBMxx-gfasPurple each have molecular weights of 49.2 kDa, 49.1 kDa, 40 kDa, 46kDa, 32.l kDa, and 49.5 kDa, respectively.
(b)Yellow-light detection of BDC shows the color of each fusion protein suspended in 20 mM Tris HCl under bluelight.
(c) Binding efficiencies of cellulose binding domains CBM2 and CBM3 toward cellulose gauze; binding efficiencies of collagen binding domains α1 and α2, chitosan binding domain CBM5, and alginate binding domain VbCBMxx toward respective hydrogel materials.