Carbohydrate sulfotransferase 11 is an enzyme that in humans is encoded by the CHST11 gene.

The protein encoded by this gene belongs to the sulfotransferase 2 family. It is localized to the golgi membrane, and catalyzes the transfer of sulfate to position 4 of the N-acetylgalactosamine (GalNAc) residue of chondroitin. Chondroitin sulfate constitutes the predominant proteoglycan present in cartilage, and is distributed on the surfaces of many cells and extracellular matrices. A chromosomal translocation involving this gene and IgH, t(12;14)(q23;q32), has been reported in a patient with B-cell chronic lymphocytic leukemia. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2011].
Function: Catalyzes the transfer of sulfate to position 4 of the N-acetylgalactosamine (GalNAc) residue of chondroitin. Chondroitin sulfate constitutes the predominant proteoglycan present in cartilage and is distributed on the surfaces of many cells and extracellular matrices. Can also sulfate Gal residues in desulfated dermatan sulfate. Preferentially sulfates in GlcA->GalNAc unit than in IdoA->GalNAc unit. Does not form 4, 6-di-O-sulfated GalNAc when chondroitin sulfate C is used as an acceptor.