YKL-40 is structurally similar to chitotriosidase (CHIT1), an active chitinase, but it lacks chitin-degrading activity while retaining chitin-binding capability. Elevated YKL-40 levels are associated with inflammatory diseases and cancers, making it a valuable biomarker. We previously reported that the W69T substitution in YKL-40 significantly reduces its chitin-binding affinity, identifying W69 as a crucial binding site. In this study, we establish a novel chitin-binding affinity evaluation method using a three-step buffer system to assess the binding strength and specificity of chitin-binding proteins and apply it to characterize YKL-40's binding mechanism. Our findings confirm that YKL-40, through its key residue W69, exhibits highly specific and robust affinity to chitin. Unlike CHIT1, which has both a catalytic domain (CatD) and a chitin-binding domain (CBD) that allow for diverse binding and degradation activities, YKL-40 lacks a CBD and is specialized for specific chitin recognition without degrading it. Comparative analysis with YKL-39, which does not contain a corresponding W69 residue, highlights the unique role of this residue in YKL-40's chitin-binding activity that is potentially linked to immune and inflammatory responses. Our evaluation method clarifies YKL-40's binding properties and provides a versatile approach applicable to other chitin-binding proteins.
- Klíčová slova
- W69 residue, YKL-39, YKL-40, catalytic domain (CatD), chitin, chitin-binding activity, chitin-binding affinity assay, chitin-binding domain (CBD), chitinase-like proteins (CLPs), chitotriosidase (CHIT1),
- MeSH
- chitin * metabolismus chemie MeSH
- hexosaminidasy * metabolismus chemie MeSH
- katalytická doména MeSH
- lidé MeSH
- protein CHI3L1 * metabolismus MeSH
- vazba proteinů * MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- CHI3L1 protein, human MeSH Prohlížeč
- chitin * MeSH
- chitotriosidase MeSH Prohlížeč
- hexosaminidasy * MeSH
- protein CHI3L1 * MeSH
