The Z mutation alters the global structural dynamics of α1-antitrypsin.

α1-Antitrypsin (α1AT) deficiency, the most common serpinopathy, results in both emphysema and liver disease. Over 90% of all clinical cases of α1AT deficiency are caused by the Z variant in which Glu342, located at the top of s5A, is replaced by a Lys which results in polymerization both in vivo and in vitro. The Glu342Lys mutation removes a salt bridge and a hydrogen bond but does not effect the thermodynamic stability of Z α1AT compared to the wild type protein, M α1AT, and so it is unclear why Z α1AT has an increased polymerization propensity.

Local conformational flexibility provides a basis for facile polymer formation in human neuroserpin.

Neuroserpin is a regulator of neuronal growth and plasticity. Like other members of the serpin family, neuroserpin undergoes a large conformational change as part of its function. Unlike other serpins such as α(1)-antitrypsin, wild-type neuroserpin will polymerize under near-physiological conditions, and will spontaneously transition to the latent state.

Cortical F-actin, the exocytic mode, and neuropeptide release in mouse chromaffin cells is regulated by myristoylated alanine-rich C-kinase substrate and myosin II.

Adrenal medullary chromaffin cells are innervated by the sympathetic splanchnic nerve and translate graded sympathetic firing into a differential hormonal exocytosis. Basal sympathetic firing elicits a transient kiss-and-run mode of exocytosis and modest catecholamine release, whereas elevated firing under the sympathetic stress response results in full granule collapse to release catecholamine and peptide transmitters into the circulation. Previous studies have shown that rearrangement of the cell actin cortex regulates the mode of exocytosis.