# Development of mumps virus-specific sialidase imaging probes through chemical modifications of sialic acid

## TL;DR

Scientists modified a probe to specifically detect mumps virus sialidase, improving its accuracy for diagnosing mumps infections.

## Contribution

The study introduces chemical modifications to a sialidase probe that enhance its specificity for mumps virus sialidase.

## Key findings

- BTP3-Neu5Ac derivatives with hydrophobic groups at the C5 position improved specificity for mumps virus sialidase.
- Linear N-acyl groups with 5–8 carbon atoms at the C5 position enhanced MuV sialidase detection accuracy.
- The modified probes could enable precise identification and diagnosis of mumps virus infections.

## Abstract

Some viruses, such as mumps virus (MuV), possess sialidases that cleave terminal sialic acids, primarily N-acetylneuraminic acid (Neu5Ac), from glycans. Previously, we developed a sialidase fluorescent imaging probe (BTP3-Neu5Ac) and visualized cells infected with sialidase–expressing viruses. However, BTP3-Neu5Ac could not specifically identify these viruses, as it reacted with a wide range of sialidases from viruses, bacteria, and mammals. Here, to confer specificity of BTP3-Neu5Ac to MuV sialidase, which features a hydrophobic cavity extending toward the C5 position of bound Neu5Ac, we evaluated BTP3-Neu5Ac derivatives containing hydrophobic groups at the C5 position of Neu5Ac moiety across various viral sialidases, including influenza A and B viruses. Linear N-acyl groups with 5–8 carbon atoms at this position improved specificity for MuV sialidase. These derivatives might enable precise identification and diagnosis of MuV infections. Our findings demonstrate that chemical modifications to Neu5Ac in BTP3-Neu5Ac can effectively modulate its specificity for viral sialidases.

The online version contains supplementary material available at 10.1038/s41598-025-26190-y.