MGAT4B

JCGG-STR009323		JCGG-STR006994

JCGG-STR009224		JCGG-STR006972

β1,4-N-Acetylglucosaminyltransferase-IV (MGAT4) transfers GlcNAc toβ1-4 of mannose on the GlcNAcβ1-2Manα1-3 structure (GlcNAcβ1-2Manα1-3Manβ1-R) synthesized by MGAT1. MGAT4 does not have activity or affinity to the glycan structure received bisect GlcNac by MGAT3. MGAT4A, which has high homology to bovine enzymes, and MGAT4B, which has low homology to bovine enzymes, are known as MGAT4. MGAT4B was cloned from human genome. Both are characterized as similar optimal pH and Mn2+ concentration, but are different in cation dependency. Co2+ can activate MGAT4B comparably to that Mn2+ does.
GNT-IV GNT-IVB

Glc	Man	Gal	GlcNAc	GalNAc	Fuc	Xyl	Neu5Ac	Neu5Gc	GlcA	IdoA	GlcN