insulin a-chain

Sulfatides are endogenous sulfoglycolipids with various biological activities in the central and peripheral nervous systems, pancreas, and immune system. They are produced from the combination of ceramide and UDP-galactose in the endoplasmic reticulum followed by sulfation in the Golgi apparatus. The ceramide portion contains variable fatty acid chain lengths, which are tissue- and pathology-dependent. Sulfatides are primarily found in the myelin sheath of oligodendrocytes and Schwann cells, with smaller chain lengths predominant during development and longer chain lengths predominant in mature cells. They accumulate in the lysosome of patients with metachromatic leukodystrophy, a disorder characterized by arylsulfatase A deficiency. Sulfatides are also located in pancreatic β-cells and inhibit insulin release from isolated rat pancreatic islet cells, suggesting a potential role in diabetes. Sulfatides can induce inflammation in glia in vitro and certain sulfatides, such as C24:1 3'-sulfo-galactosylceramide, can induce an immune response in vitro in mouse splenocytes. Sulfatides (bovine) (sodium salt) is a mixture of isolated bovine sulfatides.

InsB (9-23) is an insulin B-chain peptide that binds to a class II histocompatibility complex (MHC) allele called I-Ag7.

This peptide is a fragment of the alpha-chain of insulin amino acids 1 to 13. The insulin a-chain epitope recognized by human T cells is posttranslationally modified.

Human proinsulin, the single-chain peptide precursor of insulin, consists of the insulin A and B chains connected by the 31 amino acid C-peptide. Cleavage of proinsulin by proteolytic enzymes produces insulin and free C-peptide.