Microsomal triglyceride transfer protein large subunit is a protein that in humans is encoded by the MTTP, also known as MTP, gene.[5][6]
MTTP encodes the large subunit of the heterodimeric microsomal triglyceride transfer protein (MTP). Protein disulfide isomerase (PDI) completes the heterodimeric MTP, which has been shown to play a central role in lipoprotein assembly. Mutations in MTTP can cause abetalipoproteinemia.[6]
Apolipoprotein B48 on chylomicra and Apolipoprotein B100 on LDL, IDL, and VLDL are important for MTP binding.[citation needed]
MTP adds triglycerides to nascent chylomicrons in the intestine, and to VLDL in the liver.[7]