Hemopexinlike

Hemopexin-like refers to a conserved protein domain found in a variety of extracellular proteins that shows sequence similarity to the hemopexin family. The term is used to describe proteins or protein regions that contain an HX-like domain, which is often annotated in protein databases to indicate structural and functional relatedness to hemopexin, a plasma glycoprotein involved in heme binding.

The HX-like domain is commonly found as part of multi-domain proteins, including secreted proteases such as matrix metalloproteinases, as well as other extracellular matrix–associated proteins. The exact positioning of the HX-like domain varies among proteins, but its presence typically signals potential roles in mediating protein–protein interactions or substrate recognition rather than catalytic activity.

Functions attributed to hemopexin-like domains are diverse and context-dependent. In many cases, the HX-like domain contributes to protein–protein interactions, helps determine substrate specificity, or modulates localization within the extracellular milieu. In proteases that contain a true hemopexin-like domain, this region can influence substrate binding and interactions with inhibitors or cell-surface receptors. Some HX-like domains may retain the capacity to bind heme, whereas others do not, reflecting functional divergence within the family.

Clinical and research interest in HX-like–containing proteins stems from their roles in extracellular matrix remodeling, development, inflammation, wound healing, and cancer biology. Structural and comparative studies of HX-like domains aid in predicting function for uncharacterized proteins and in modeling domain architecture across diverse species.