Desmosine: A rare amino acid found in elastin, formed by condensation of four molecules of lysine into a pyridinium ring.Isodesmosine: 2-(4-Amino-4-carboxybutyl)-1-(5-amino-5-carboxypentyl)-3,5-bis(3-amino-3-carboxypropyl)pyridinium. A rare amino acid found in elastin, formed by condensation of four molecules of lysine into a pyridinium ring.ElastinTropoelastin: A salt-soluble precursor of elastin. Lysyl oxidase is instrumental in converting it to elastin in connective tissue.Elastic Tissue: Connective tissue comprised chiefly of elastic fibers. Elastic fibers have two components: ELASTIN and MICROFIBRILS.Ligaments: Shiny, flexible bands of fibrous tissue connecting together articular extremities of bones. They are pliant, tough, and inextensile.Tissue Survival: The span of viability of a tissue or an organ.Emphysema: A pathological accumulation of air in tissues or organs.Leukocyte Elastase: An enzyme that catalyzes the hydrolysis of proteins, including elastin. It cleaves preferentially bonds at the carboxyl side of Ala and Val, with greater specificity for Ala. EC 188.8.131.52.Protein-Lysine 6-Oxidase: An enzyme oxidizing peptidyl-lysyl-peptide in the presence of water & molecular oxygen to yield peptidyl-allysyl-peptide plus ammonia & hydrogen peroxide. EC 184.108.40.206.