THE MODULUS OF ELASTICITY OF LOBSTER AORTA MICROFIBRILS

The presence of elastic fibres in the extracellular matrix (ECM) provi des physiologically important elastic properties for many tissues. Unt il recently, microfibrils, one component of the ECM, were thought prim arily to serve as a scaffolding on which elastin is deposited during d evelopment to form elaunin fibres [1]. The most prominent protein that forms mammalian microfibrils is fibrillin. It is known that mutations in the fibrillin gene cause a heterogenous connective tissue disease called Marfan syndrome [2], so information on mechanical properties of microfibrils or their role in tissue function would be useful. Microf ibrils are also found in the ECM of some invertebrate tissues, and the re is growing evidence that the protein forming the structure is homol ogous to mammalian fibrillin [3, 4]. It has been shown that the microf ibril-based arterial wall of the lobster has viscoelastic properties [ 5], and we have now utilized this primitive artery to measure the modu lus of elasticity of microfibrils. It is similar to that of the rubber -like protein elastin.