| Method |
P.3 right column top paragraph: "CS [Chondroitin sulfate] has several isomers which have different degrees of sulfonation and binding sites of sulfonate groups [refs 24–26]. Generally, intact CS chains show various MW and a range of their MW is extremely wide from thousands to hundreds of thousands [refs 2–4]. Based on this fact, [investigators] firstly fractionated commercially available CS by low-pressure gel chromatography to prepare CS within a strictly limited range of average MW. Two different types of CS samples were applied: one was derived from whale cartilage which is mainly composed of CS-A structure [GlcA (β1-3) GalNAc4S], and the other was from bovine tracheal cartilage which is mainly composed of CS-A structure [GlcA (β1-3) GalNAc4S] [refs 27, 28]. Sephadex G100 Superfine, by which the available fractionation range is from 1 to 100 kDa, was employed for preparation of CS as the average MW of CS from whale cartilage and bovine tracheal cartilage was 21 kDa and 15 kDa, respectively. The structure of each fractionated CS was confirmed by the HPLC for disaccharide analysis and 1H NMR (data not shown). The extent of fractionation of CS was confirmed by applying gradient polyacrylamide gel electrophoresis (PAGE), and [they] confirmed that [they] could obtain CS with strictly limited range of MW (Figure 1 and Table 1). Six fractionated CSs from whale cartilage, of which original average MW was 21 kDa, were estimated from 7 to 29 kDa. As for CS from bovine tracheal cartilage, the range of MW was from 6 to 33 kDa." |