Monovalent goat antibody fragments (Fab) that were monospecific for human fibrinogen were isolated by affinity chromatography on fibrinogen-Sepharose and used as a direct probe for the involvement of fibrinogen in platelet aggregation and the release reaction. The antifibrinogen Fab inhibited aggregation of washed human platelets induced by thrombin (0.1-10 U/ml) by 50-95%, but had no effect on...

Human liver sections were stained with anti-human serum albumin and/or anti-human fibrin monomer fluorescent conjugates. Approximately 10 per cent of the hepatic cells stained specifically for human serum albumin,1 per cent for fibrinogen, and 0.1 per cent for both. Approximately 18 per cent of the Kupffer cells stained specifically for human serum albumin and 33 per cent for fibrinogen. Staini...

The recA protein of Escherichia coli promotes the complete exchange of strands between full length linear duplex and single-stranded circular DNA molecules. An early step in this reaction consists of the binding of recA protein to single-stranded DNA. In the presence of ATP and the single-stranded DNA binding protein, recA protein and single-stranded DNA interact to form a complex whose stabili...

Protein kinase autophosphorylation is a common regulatory mechanism in cell signaling pathways. Crystal structures of several homomeric protein kinase complexes have a serine, threonine, or tyrosine autophosphorylation site of one kinase monomer located in the active site of another monomer, a structural complex that we call an "autophosphorylation complex." We developed and applied a structura...

The Saccharomyces cerevisiae Taz1 protein is the orthologue of human Tafazzin, a protein that when inactive causes Barth Syndrome (BTHS), a severe inherited X-linked disease. Taz1 is a mitochondrial acyltransferase involved in the remodeling of cardiolipin. We show that Taz1 is an outer mitochondrial membrane protein exposed to the intermembrane space (IMS). Transport of Taz1 into mitochondria ...

The replication system of bacteriophage T4 uses a trimeric ring-shaped processivity clamp (gp45) to tether the replication polymerase (gp43) to the template-primer DNA. This ring is placed onto the DNA by an ATPase-driven clamp-loading complex (gp44/62) where it then transfers, in closed form, to the polymerase. It generally has been assumed that one of the functions of the loading machinery is...