Pig thyroid spectrin

Abstract
Thyroid spectrin has been obtained pure from pig thyroid glands. This protien, composed of two non‐identical polypeptide chains of 240 kDa and 235 kDa, appears to possess the same structural and immunological properties as well as the same calmodulin and actin‐binding properties as brain spectrin. Through cross‐linking of actin filaments it is a potent gelation factor for F‐actin solutions. It represents one of the major protein of the cytoskeleton underlying the thyroid plasma membrane together with myosin, α‐actinin and actin.