Question

Which of the following aspects of collagen would be directly affected by a defect in procollagen peptidase?

A) synthesis
B) secretion
C) extracellular assembly
D) binding to fibronectin
E) all of the above

Answer 1

A defect in procollagen peptidase directly impacts the extracellular assembly (C) of collagen by hindering the removal of terminal propeptides necessary for the proper formation of collagen fibers.

Step-by-step explanation:

The enzyme procollagen peptidase is involved in the processing of procollagen into collagen by removing the terminal propeptides. This step is crucial for the extracellular assembly of collagen fibers, as it allows collagen molecules to assume their proper triple-helical structure and to associate with each other to form fibrils.

Therefore, a defect in procollagen peptidase would directly affect extracellular assembly (C) of collagen. This is because, without the activation step that procollagen peptidase provides, the collagen would not be processed into its mature form and would not be able to assemble into functional fibrils outside the cell.