Title : [The primary structure of human free secretory component and the arrangement of disulfide bonds]
Abstract :
- The amino-acid sequence and the arrangement of the disulfide bonds of the human free secretory component were completely elucidated by the methods of protein chemistry
- The free secretory component is a monomeric glycoprotein (Mr approximately 86000), consisting of 558 amino acids with 7 carbohydrate chains bound to asparagine
- The protein contains 20 cysteine residues but, as a special feature, no methionine
- The polypeptide chain is divided into five regions of internal homology, 104 to 114 amino acids in length
- The 20 cysteine residues form 10 disulfide bonds, 9 of which confirm the internal homology by their characteristic arrangement
- The free secretory component also shows homology to immunoglobulins in some sections
- A computer-supported tertiary structure is proposed for the free secretory component