Coordination Bonds of Ironsixcoordinationbonds- four to nitrogen atoms in the flat porphyrin ringtwoperpendiculartotheporphyrintozo(b)CH(c)
GlobinsAreaFamilyofOxygen-BindingProteinsglobins=widespreadproteinfamilyCarboxyltermi-highlyconservedtertiary structure:HicsHisF8eight a-helicalsegmentsconnectedbyAminoterminusbends (globinfold)一mostfunctioninO2transportorstorage
Types of Globinsfourtypesinhumansandothermammals-myoglobin=monomeric,facilitatesO,diffusioninmuscletissuehemoglobin=tetrameric,responsibleforO2transportinthebloodstreamneuroglobin=monomeric,expressedlargelyinneuronstoprotectthebrainfromlowO2orrestrictedbloodsupplycytoglobin=monomeric,regulateslevelsofnitricoxide,alocalizedsignalformusclerelaxation
MyoglobinHas a Single Binding SiteforOxygenmyoglobin:153residues+onemoleculeofheme-bendsnamedaftertheα-helicalsegmentstheyconnectHis93=ninety-thirdresidefromtheaminoterminalendHisF8=eighthresidueinahelixF
Protein-Ligand Interactions CanBeDescribedQuantitivelyasimpleequilibriumexpressiondescribesthereversible binding of aprotein (P)toa ligand (L)P + L= PLNochemistry
No chemistry