Gellan Gum Gets Its Own Molecular Highlighter

Gellan gum is a thick, gooey ingredient found in many foods. It helps sauces and desserts keep their shape. Scientists use special tools called carbohydrate-binding modules to study sugar chains. These tools act like probes that stick to specific sugars. Before this work, no one had found a probe just for gellan gum.

Researchers created a new protein piece named ClCBM96. It comes from a suspected gellan gum enzyme. They produced it in a host cell. This piece grabs onto gellan gum very specifically. Scientists measured how strongly it binds. The number came out to 1.5 times 10 to the fifth power per molar.

Next, they looked at the shape of ClCBM96 using crystals. The picture resolved at 1.81 angstroms. It shows a common fold known as a beta sandwich. By swapping out single building blocks, they found four key spots. These are W28, K32, T37, and R39. Changing any of them weakens the grip on gellan gum.

To make gellan gum visible, they fused ClCBM96 with a green fluorescent protein. The result glows where gellan gum sits. This probe works for looking at samples in place. It marks the first binding module ever described for gellan gum. Other scientists can now use it to explore this food additive further.