Thirteen recombinant alpha A-crystallin mutants were constructed that differed in the type of amino acid residue directly preceding the sole amine donor lysine for transglutaminases in this protein. The capacity of these mutants to be cross-linked to amine acceptor substrates by tissue transglutaminase and factor XIII was assessed. Two different biotinylated glutamine-containing oligopeptides w...

Plasma factor XIII is composed of two subunits, a and b, whereas platelet and other intracellular zymogens have only a-subunits. The catalytic subunit, a, is the same in all forms. In order to characterize the interactions of 1- with b-chains in the plasma zymogen and a-chains with other molecules and to correlate factor XIII activity with a-protein, a specific, sensitive radioimmunoassay was d...