Malectin

Malectin (MLEC) is a carbohydrate-binding protein that preferentially binds Glc2-N-glycan structures and is thought to participate in early steps of protein N-glycosylation (UniProt: Q14165). The protein functions in glycoprotein quality control and maturation within the endoplasmic reticulum, a critical pathway for proper protein folding and cellular homeostasis.

In Alzheimer's Disease, malectin shows increased abundance in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). Across the analyzed subcellular fractions from a TMT-labeled quantitative proteomics experiment, malectin exhibits a mean log2 fold-change of 0.66, indicating modest up-regulation in AD brain. This elevation may reflect altered ER-resident protein processing or compensatory glycosylation responses in the disease context.