Title : Completion of the primary structure of human high-molecular-mass kininogen
Abstract :
- The amino acid sequence of the entire heavy chain and evidence for its evolution by gene triplication
- The amino acid sequence of the heavy chain of human high-molecular-mass kininogen has been determined
- It completes the primary structure of the high-Mr kininogen molecule
- The heavy chain contains 362, the total kininogen molecule 626 amino acid residues
- Three carbohydrate side chains were found in the heavy chain, all of them N-glycosidically linked to asparagine , which is present in the acceptor sequon Asn-Xaa- Thr (or - Ser ); one additional potential glycosylation site devoid of a sugar side chain is found at position 30
- There is a high degree of homology between the heavy chains of human high-Mr kininogen and bovine high-Mr kininogen (74% identity), or rat T-kininogen (61%)
- Comparison of the primary structure of human high-Mr kininogen with that of human low-Mr kininogen predicted from its cDNA sequence , reveals that the heavy chains of the two human kininogens are completely identical
- Two heavy chain segments believed to contain the reactive sites for cysteine proteinase inhibition show an extensive sequence homology with other mammalian cysteine proteinase inhibitors
- Within the heavy chain of human high-Mr kininogen are repetitive units strongly suggesting that the heavy chain of human kininogens has evolved from at least two ancestral units by a series of gene duplication and fusion events