Andrew P. Laudano 2026-11-05
Andrew P. Laudano is a biochemistry researcher whose work with Russell F. Doolittle used synthetic peptides to investigate fibrin assembly. A historical university catalog records his UC San Diego doctorate in 1981 and lists him as an emeritus faculty member in 2013–2014.[ref]
Andrew P. Laudano entry in the University of New Hampshire 2013–2014 faculty catalog. Laudano,AndrewP entry: degree and historical faculty classification
In the 1978 experiment, Gly-Pro-Arg-Pro bound fibrinogen and fragment D but not the central fragment E. The shorter Gly-Pro-Arg bound less tightly and inhibited polymerization less effectively. These comparisons linked the structure of a small peptide to its ability to disrupt a larger molecular assembly.[ref]
Synthetic peptide derivatives that bind to fibrinogen and prevent the polymerization of fibrin monomers by Andrew P. Laudano and Russell F. Doolittle. Abstract: fragment-specific binding and tripeptide/tetrapeptide comparison
An illuminating control is a fragment that does not bind: it helps localize the interacting region rather than merely showing that “some protein” captures the peptide. Comparing related sequences adds another constraint. Together the tests connect binding affinity, molecular location and the observable formation of a fibrin network.
Fibrin knob-hole interaction 2026-11-05
A fibrin knob-hole interaction is the binding of an exposed short peptide segment on one fibrin molecule to a complementary pocket on another molecule. Thrombin removes Fibrinopeptide A to expose the A knob and Fibrinopeptide B to expose the B knob. The corresponding a and b holes lie in different distal protein domains. These intermolecular contacts help assemble a fibrin network.[ref]
Polymerization of fibrin: specificity, strength, and stability of knob-hole interactions studied at the single-molecule level by Rustem I. Litvinov and others. Figure1: knob exposure and the locations of complementary holes
A decisive test uses a small competing peptide. The synthetic sequence Gly-Pro-Arg-Pro mimics the exposed A-knob end: it binds fibrinogen and its distal fragment D and inhibits fibrin polymerization. A soluble imitation can occupy a pocket without connecting two full-sized molecules, disrupting the assembly.[ref]
Synthetic peptide derivatives that bind to fibrinogen and prevent the polymerization of fibrin monomers by Andrew P. Laudano and Russell F. Doolittle. Abstract: binding to fibrinogen/fragment D, lack of binding to fragment E, and inhibition
Optical tweezers later measured individual rupture events, with forces around – under the study's conditions. Removing the required sites or adding the A-knob mimic suppressed the strong events. The assay supported specific A:a binding; it did not detect a comparable B-mediated force contribution under those conditions.[ref]
Polymerization of fibrin: specificity, strength, and stability of knob-hole interactions studied at the single-molecule level by Rustem I. Litvinov and others. Abstract: rupture-force distributions and peptide-inhibition controls
Russell F. Doolittle 2026-11-05
Russell F. Doolittle was a researcher in protein structure and molecular evolution at UC San Diego. His investigations connected the chemistry of fibrinogen and fibrinopeptides with comparisons of inherited molecular differences among species.[ref]
Russell Doolittle in University of California In Memoriam. Memorial: fibrinopeptide comparisons, fibrinogen studies and evolutionary relationships
With Andrew P. Laudano, Russell F. Doolittle tested synthetic peptides resembling the exposed ends of fibrin chains. Gly-Pro-Arg-Pro bound fibrinogen and its distal fragment D and inhibited fibrin polymerization, helping locate a binding interaction involved in assembly.[ref]
Synthetic peptide derivatives that bind to fibrinogen and prevent the polymerization of fibrin monomers by Andrew P. Laudano and Russell F. Doolittle. Abstract: synthetic peptides, fragment binding and inhibition
The experiment gives a small molecule an explanatory role: an imitation of one binding element can occupy a site without connecting two full-sized molecules. Interrupting network formation in this way tests a specific molecular contact. The same interest in protein sequences also supports a different kind of inference: comparing related molecules across species can reveal evolutionary relationships.