Human recombinant alpha1(V) collagen chain. Homotrimeric assembly and subsequent processing

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Collagen V is a fibrillar collagen crucial for tissue structure.
• Understanding recombinant collagen processing is key for biomaterials and therapeutics.

Purpose of the Study:

• To produce and characterize recombinant human alpha1(V) collagen chains.
• To investigate the folding, stability, and processing of alpha1(V) collagen.

Main Methods:

• Transfection of human embryonic kidney cells (293-EBNA) with alpha1(V) collagen gene.
• Analysis of secreted recombinant collagen using electron microscopy, circular dichroism, pepsin resistance assays, N-terminal sequencing, and collagenase digestion.
• Investigation of cell homogenates and disulfide-linked polypeptides.

Main Results:

• High yields of secreted recombinant alpha1(V) collagen (15 microgram/ml) were achieved.
• Recombinant alpha1(V) collagen formed stable triple helices with a melting temperature of 37.5°C.
• Evidence of novel N-terminal and C-terminal processing, including rapid C-propeptide cleavage after secretion.
• Identification of a kink in the triple helix potentially targeted by proteases.

Conclusions:

• The study demonstrates successful production of functional recombinant alpha1(V) collagen.
• Novel processing pathways for alpha1(V) collagen were identified, differing from heterotrimeric forms.
• These findings may explain the low recovery of homotrimeric alpha1(V) collagen in tissues and have implications for collagen-based applications.