Biochemistry of protein tyrosine nitration in cardiovascular pathology.

Several pathologies of the cardiovascular system are associated with an augmented production of nitric oxide and/or superoxide-derived oxidants and/or alteration in the antioxidant detoxification pathways that lead to nitroxidative stress. One important consequence of these reactive intermediates at the biochemical level is the nitration of protein tyrosines, which is performed through either of two of the relevant nitration pathways that operate in vivo, namely peroxynitrite and heme peroxidase-dependent nitration. Proteins nitrated at tyrosine residues have been detected in several compartments of the cardiovascular system. In this review a selection of nitrated proteins in plasma (fibrinogen, plasmin, Apo-1), vessel wall (Apo-B, cyclooxygenase, prostaglandin synthase, Mn-superoxide dismutase) and myocardium (myofibrillar creatine kinase, alpha-actinin, sarcoplasmic reticulum Ca(2+) ATPase) are analyzed in the context of cardiovascular disease. Nitration of tyrosine can affect protein function, which could directly link nitroxidative stress to the molecular alterations found in disease. While some proteins are inactivated by nitration (e.g. Mn-SOD) others undergo a gain-of-function (e.g. fibrinogen) that can have an ample impact on the pathophysiology of the cardiovascular system. Nitrotyrosine is also emerging as a novel independent marker of cardiovascular disease. Pharmacological strategies directed towards inhibiting protein nitration will assist to shed light on the relevance of this post-translational modification to human cardiovascular pathology.