TheobservationthatabloodclotspontaneouslydissolveswasfirstdescribedbyDenys in1889. Subsequently, thebloodclottingsystemwasshowntobeinvolvedintumor growth. Forexample, asearlyas1925, Fisherreportedthataviantissueexplantstrans- formedtomalignancybyvirusesgeneratedhighlevelsoffibrinolyticactivityundercon- ditionsinwhichculturesofnormalcellsdidnot. In1958, theconceptthatan equilibriumexistedbetweenthetendencyofbloodtoclotandtoremainfluidwaspro- posedbyAstrup. Atthattime, itwasbelievedthatthishemostaticbalancewasexplained bytheabilityofpolymerizingfibrintoorchestrateitsownclearancebystimulatingfib- rinolyticactivity. Sincethesepioneeringstudies, considerableinformationhasaccumu- latedthathasdefinedthecomponentsofthecoagulationandfibrinolyticsystemsand howtheyareinvolvedinphysiologicalandpathophysiologicalprocesses. Plasminogen: Structure, activation, and regulationfocusesonthebasicprinciplesandrecentdevelop- mentsintheplasminogen/plasminresearchfieldandhowtheseresultsprovideacon- ceptualframeworkforanunderstandingofthephysiologicalroleofplasminogenin healthanddisease.Theenzymaticcascadetriggeredbyactivationofplasminogenhasbeenimplicated inavarietyofnormalandpathologicaleventssuchasfibrinolysis, woundhealing, tis- sueremodeling, embryogenesis, angiogenesis, andtheinvasionandmetastasisoftumor cells. Thisimpressivelistofphysiologicalfunctionsforplasminogenreinforcesthewide diversityofrolesthatplasminogenplaysinvariousphysiologicalprocesses. Productive plasmingenerationrequirestheassemblyofbothplasminogenactivatorsandplasmino- genonasolidsupportsuchasthefibrinpolymerorthecellsurface. Theregulationof plasminproductioninvolvesacomplexinterplaybetweentheseplasminogenactivators, plasminogenactivatorinhibitors, andplasmininhibitors. Clearly, theexplosivegrowth inthisresearchfieldandthemanyexcitingdiscoveriessuggeststhattheresearchefforts inthenextdecadewillrevealthemechanismsbywhichthecomponentsoftheplas- minogensysteminteractandregulatebothplasminactivationandfunctionatacellular level. Plasminogen: Structure, activation, and regulationisdividedintotwosections. Thefirstsectiondealswiththestructureandregulationofplasminogen.Thechapters inthissectionrangefromdiscussionsofthestructureofplasminogenandtheregulation oftheplasminogengenetodiscussionsofthestructureandregulationofplasminogen activatorsandplasminogenactivatorinhibitors. Alsoexaminedistherelativelynewdata concerningthegenerationofanti-angiogenicmoleculesfromplasminogen. Thesecond sectiondealswiththephysiologicalandpathophysiologicalrolesofplasminogenaswell astheconsequencesofplasminogengeneknockout. Discussionsinthissectioninclude examinationoftheroleofplasminogeninhematopoieticmalignancies, tumorcell progression, angiogenesis, mammaryglandinvolution, woundhealing, andbone readsorption. xi xii Preface Inclosing, Iwouldliketothankmyadministrativeassistant, Ms. ViSommerfeld, for herinvaluableassistanceandtimelesseffortswiththeorganizationandeditingofthebook. Lastly, Iwouldliketoacknowledgetheeffortsoftheauthorsoftheindividualchapters, whoareauthorities inthisfield, foragreeingtotaketimefrombusyschedulestoprovide thesechaptersinatimelyfashion. DavidMortonWaisman Contents Part I. Plasminogen: Structure and Regulation 1. Human Plasminogen: Structure, Activation, and Function FrancisJ. Castellino and Victoria A. Ploplis 1. Introduction 3 2.StructureofHumanPlasminogen...3 2. 1. PrimaryProteinStructure...3 2. 2. GeneOrganization 5 3. ActivationofHumanPlasminogen...6 3. 1. ActivationbyPhysiologicalActivators 7 3. 1. 1. Urokinase-typePlasminogenActivator...7 3. 1. 2. Tissue-typePlasminogenActivator...8 3. 2. ActivationbyBacterial-derivedPlasminogenActivators...9 3. 2. 1. Streptokinase 9 3. 2. 2. Staphylokinase...9 4. TargetsforPlasminActivity...9 5. DysplasminogenemiasandPhenotypicManifestations 10 6. Conclusions 11 References...11 2. Plasminogen Activators: Structure and Function Vincent Ellis 1. Introduction ...19 2. SerineProteases...20 3. UrokinasePlasminogenActivator, uPA...21 3. 1. Serine
