Figure 9
GRLN-like activity of stingray GRLN-LP. (A) Dose-response effects of rat GRLN (open circle) and unglycosylated stingray GRLN-LP (closed circle) on intracellular Ca2+ concentrations in rat GHS-R1a-expressing cell line. Values represent the means (± SE) of samples tested in triplicate. (B) Reduction of GRLN-like activity after the native stingray GRLN-LP was catalyzed. The changes in intracellular Ca2+ levels are shown for both the native (upper) and catalyzed (lower) peptides. The increases in intracellular Ca2+concentrations decreased after the native stingray GRLN-LP was catalyzed by O-glycanase. A dose response was obtained by diluting the original sample 1/3 and 1/10.