Identification of novel fish sialidase genes responsible for KDN-cleaving activity

Kazuhiro Shiozaki, Keiya Uezono, Go Hirai, Akinobu Honda, Masaya Minoda, Ryuta Wakata

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN) is a minor component of sialic acids detected in vertebrates, such as human cancer cells, rat liver, and fish tissues. Although the enzyme activity of KDN-cleaving sialidase (KDN-sialidase) has been detected in rainbow trout, the gene responsible for its expression has not been identified in vertebrates. We evaluated sialidases in human and various fish for their KDN-cleaving activity using an artificial substrate, methylumbelliferyl-KDN (MU-KDN). Four of the human sialidases tested (NEU1, NEU2, NEU3, and NEU4) did not hydrolyze MU-KDN. Although most fish Neu1s showed negligible KDN-sialidase activity, two Neu1b sialidases from Oreochromis niloticus and Astyanax mexicanus, a paralog of Neu1, exhibited a potent KDN-sialidase activity. Further, O. niloticus and Oryzias latipes Neu3a exhibited a drastically high KDN-sialidase activity, while Danio rerio Neu3.1 showed moderate activities and other Neu3 proteins exhibited little activity. All the Neu4 sialidases tested in fish cleaved KDN and Neu5Ac from MU-KDN and MU-Neu5Ac, respectively, with equivalent potential. To our knowledge, this is the first report to identify KDN-sialidase genes in vertebrates and we believe that KDN-sialidase activity could be conserved among fish Neu4s.

Original languageEnglish
Pages (from-to)745-753
Number of pages9
JournalGlycoconjugate Journal
Issue number6
Publication statusPublished - Dec 2020

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Identification of novel fish sialidase genes responsible for KDN-cleaving activity'. Together they form a unique fingerprint.

Cite this