HUMAN FIBRINOGEN - ANTICIPATING A 3-DIMENSIONAL STRUCTURE

The principal component of blood clots is a protein meshwork called fi brin. The precursor protein, fibrinogen, occurs in a soluble form in t he blood plasma where it is activated by thrombin when and if the need arises. More than a century after first being purified, fibrinogen ha s yet to have its detailed 3-dimensional structure revealed. The situa tion is changing rapidly, however, and crystallographic studies in pro gress in several laboratories on a variety of fragments and complexes may soon reveal not only its structure but also the subtleties of how this large glycoprotein is transformed into a fibrin clot.