21. Urine odor in cystinuria has a smell of rotten eggs due to the increase in cystine . 22. But if there is a defect in the carrier protein, cystine is accumulated in lysosomes. 23. Omega, delta and kappa families of conotoxins have a knottin or inhibitor cystine knot scaffold. 24. These also selectively reduce the cystine bonds, but are much weaker and work more slowly. 25. This causes an arginine to cystine substitution at amino acid position 83, a conserved location. 26. The growth factor cystine knot ( GFCK ) was first observed in the structure of Nature. 27. Medicinally, it may be used to control kidney stones derived from either uric acid or cystine . 28. However, it is the combination of methionine and cystine which is considered for completeness of a protein. 29. The notch extracellular domain is composed primarily of small cystine -rich motifs called EGF-like repeats. 30. Although tissue damage might depend on cystine accumulation, the mechanisms of tissue damage are not fully understood.
