American Society of Hematology
Original Item ID
Fibrin molecules polymerize to double-stranded fibrils by intermolecular end-to-middle domain pairing of complementary polymerization sites, accompanied by fibril branching to form a clot network. Mass/length measurements on scanning transmission electron microscopic images of fibrils comprising branch points showed two types of junctions. Tetramolecular junctions occur when two fibrils converge, creating a third branch with twice the mass/length of its constituents. Newly recognized trimolecular junctions have three fibril branches of equal mass/length, and occur when an extraneous fibrin molecule initiates branching in a propagating fibril by bridging across two unpaired complementary polymerization sites. When trimolecular junctions predominate, clots exhibit nearly perfect elasticity.
Mosesson, Michael W.; DiOrio, James P.; Siebenlist, Kevin R.; Wall, Joseph S.; and Hainfeld, James F., "Evidence for a Second Type of Fibril Branch Point in Fibrin Polymer Networks, the Trimolecular Junction" (1993). Biomedical Sciences Faculty Research and Publications. 233.
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