Cross Aminopropionitrile

Aminopropionitrile (present in sweet peas) covalently inactivates lysyl oxidase, preventing intramolecular cross-linking of collagen and causing abnormalities in joints, bones, and blood vessels. 

Osteolathyrism is a disease characterized by lameness, skeletal deformities, aortic aneurysms, and slowing or cessation of body growth. Certain aminonitriles are known to cause osteolathyrism in several animal species aminoacetonitrile, 3-aminopropionitrile, and 3-amino-2-methylpropionitrile are potent inducers of this disease. It is believed that the basis of their ability to cause osteolathyrism is due to their ability to inhibit lysine oxidase, an enzyme important in cross-linking of collagen and formation of connective tissue. While no reports of these substances causing osteolathyrism in humans have appeared, it seems plausible that these substances could cause this disease in humans because they are known to cause it in a variety of experimental animals. 

Covalent cross-links both between and within the tropocollagen molecules confer strength and rigidity on the collagen fiber. These cross-links are formed between Lys and its aldehyde derivative allysine. Allysine is derived from Lys by the action of the copper-containing lysyl oxidase which requires pyridoxal phosphate for activity. The disease lathyrism is caused by the inhibition of lysyl oxidase by the chemical (3-aminopropionitrile in sweet pea seeds, and results in defective collagen due to the lack of cross-links. 

In lathyrism, the /3-aminopropionitrile inhibits cross-linking generated by lysyl oxidase. 

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