TABLE 5.

Selected torsion angles of chondroitin 4-sulfate structures

Torsion angles were calculated using COOT according to IUPAC rules for naming of polysaccharide conformations. β(1–4), Φ = O5(i)-C1(i)-O1(i)-C4(i−1) and Ψ = C1(i)-O1(i)-C4(i−1)-C3(i−1); β(1–3) Φ = O5(i)−C1(i)-O1(i)-C3(i−1) and Ψ = C1(i)-O1(i)-C3(i−1)-C2(i−1).

C4-S structure	Torsion angle Φ	Torsion angle Ψ	Torsion angle Φ	Torsion angle Ψ
	ASG4-BDP3 (β(1–4))	ASG4-BDP3 (β(1–4))	BDP5-ASG4 (β(1–3))	BDP5-ASG4 (β(1–3))
Fiber (sodium salt)	−79.9	110.5	−86.4	−110.7
Fiber (calcium salt)	−97.8	65.5	−79.6	−132.0
WT catK·C4-S	−70.6	126.8	56.3	−116.6
M5 variant catK·C4-S	−72.3	126.1	−85.3	−99.3