Encimi kot tarče učinkovin

Encimi kot tarče učinkovin doc. dr. Janez Ilaš 1. december 2011 1

Uvod Biokemija 2. letnik Predavanje št. 5: Encimi uvod 2011 encimi so KATALIZATORJI globularni proteini, ki za svoje nemoteno delovanje potrebujejo ohranjeno primarno, sekundarno, terciarno in kvartarno strukturo holoencim = apoencim + kofaktorji ribocimi Predavanje št. 6: Encimi prezentacija 2011 hitrost encimske reakcije Michaelis-Mentnova enačba encimska inhibicija koencimi in prostetične skupine alosterični modulatorji 2

Tarče zdravilnih učinkovin Jedrni receptorji 4% Transporterji 4% Ionski kanali 7% Drugi receptorji 4% Različno 2% Integrini 1% DNK 1% Encimi 47% GPCR 30% 3

Encimski razredi 4

Oksidoreduktaze Aldehyde dehydrogenase Inhibitor Disulfiram Monoamine oxidases (MAOs) MAO-A inhibitor Tranylcypromine, moclobemide Cyclooxygenases (COXs) MAO-B inhibitor COX1 inhibitor COX2 inhibitor Tranylcypromine Vitamin K epoxide reductase Inhibitor Warfarin, phenprocoumon Aromatase Inhibitor Exemestane Lanosterol demethylase (fungal) Inhibitor Azole antifungals Lipoxygenases Inhibitor Mesalazine 5-lipoxygenase inhibitor Acetylsalicylic acid, profens, acetaminophen and dipyrone (as arachidonylamides) Acetylsalicylic acid, profens, acetaminophen and dipyrone (as arachidonylamides) Zileuton Thyroidal peroxidase Inhibitor Thiouracils Iodothyronine-5 deiodinase Inhibitor Propylthiouracil Inosine monophosphate dehydrogenase Inhibitor HMG-CoA reductase Inhibitor Statins Mycophenolate mofetil 5α-Testosterone reductase Inhibitor Finasteride, dutasteride Dihydrofolate reductase (bacterial) Inhibitor Trimethoprim Dihydrofolate reductase (human) Inhibitor Methotrexate, pemetrexed Dihydrofolate reductase (parasitic) Inhibitor Proguanil Dihydroorotate reductase Inhibitor Leflunomide Enoyl reductase (mycobacterial) Inhibitor Isoniazid Squalene epoxidase (fungal) Inhibitor Terbinafin Δ14 reductase (fungal) Inhibitor Amorolfin Xanthine oxidase Inhibitor Allopurinol 4-Hydroxyphenylpyruvate dioxygenase Inhibitor Nitisinone Ribonucleoside diphosphate reductase Inhibitor Hydroxycarbamide 5

Transferaze Protein kinase C Inhibitor Miltefosine Bacterial peptidyl transferase Inhibitor Chloramphenicol Catecholamine-O-methyltransferase Inhibitor Entacapone RNA polymerase (bacterial) Inhibitor Ansamycins Reverse transcriptases (viral) Competitive inhibitors Zidovudine Allosteric inhibitors Efavirenz DNA polymerases Inhibitor Acyclovir, suramin GABA transaminase Inhibitor Valproic acid, vigabatrin Tyrosine kinases PDGFR/ABL/KIT inhibitor Imatinib EGFR inhibitor VEGFR2/PDGFRβ/KIT/FLT3 VEGFR2/PDGFRβ/RAF Erlotinib Sunitinib Sorafenib Glycinamide ribonucleotide formyl transferase Inhibitor Pemetrexed Phosphoenolpyruvate transferase (MurA, bacterial) Inhibitor Fosfomycin Human cytosolic branched-chain aminotransferase (hbcatc) Inhibitor Gabapentin Transferases Protein kinase C Inhibitor Miltefosine Bacterial peptidyl transferase Inhibitor Chloramphenicol Catecholamine-O-methyltransferase Inhibitor Entacapone RNA polymerase (bacterial) Inhibitor Ansamycins Reverse transcriptases (viral) Competitive inhibitors Zidovudine Allosteric inhibitors Efavirenz DNA polymerases Inhibitor Acyclovir, suramin GABA transaminase Inhibitor Valproic acid, vigabatrin Tyrosine kinases PDGFR/ABL/KIT inhibitor Imatinib 6

Hydrolaze Aspartyl proteases (viral) (proteases) HIV protease inhibitor Saquinavir, indinavir Bacterial serine protease Direct inhibitor β-lactams Bacterial lactamases (serine proteases) Direct inhibitor Sulbactam Human antithrombin (serine proteases) Activator Heparins Human plasminogen (serine proteases) Activator Streptokinase Human coagulation factor (serine proteases) Activator Factor IX complex, Factor VIII Human factor Xa (serine proteases) Inhibitor Fondaparinux Human ACE (metalloproteases) Inhibitor Captopril Human HRD (metalloproteases) Inhibitor Cilastatin H. carboxypeptidase A (Zn) (metalloproteases) Inhibitor Penicillamine Human enkephalinase (metalloproteases) Inhibitor Racecadotril 26S proteasome Inhibitor Bortezomib Esterases AChE inhibitor Physostigmine AChE reactivators Obidoxime PDE inhibitor Caffeine PDE3 inhibitor Amrinon, milrinone PDE4 inhibitor Papaverine PDE5 inhibitor Sildenafil HDAC inhibitor Valproic acid HDAC3/HDAC7 inhibitor Carbamezepine Glycosidases (viral) α-glycosidase inhibitor Zanamivir, oseltamivir Glycosidases (human) α-glycosidase inhibitor Acarbose Lipases Gastrointestinal lipases inh. Orlistat Phosphatases Calcineurin inhibitor Cyclosporin Inositol polyphosphate Lithium ions phosphatase inhibitor GTPases Rac1 inhibitor 6-Thio-GTP (azathioprine metabolite) Phosphorylases Bacterial C55-lipid phosphate dephosphorylase inhibitor Bacitracin 7

Liaze DOPA decarboxylase Inhibitor Carbidopa Carbonic anhydrase Inhibitor Acetazolamide Histidine decarboxylase Inhibitor Tritoqualine Ornithine decarboxylase Inhibitor Eflornithine Soluble guanylyl cyclase Activator Nitric acid esters, molsidomine Izomeraze Alanine racemase Inhibitor D-Cycloserine DNA gyrases (bacterial) Inhibitor Fluoroquinolones Topoisomerases Topoisomerase I inhibitor Irinotecan Topoisomerase II inhibitor Etoposide Δ8,7 isomerase (fungal) Inhibitor Amorolfin Ligaze Dihydropteroate synthase Inhibitor Sulphonamides Thymidylate synthase (fungal and human) Inhibitor Fluorouracil1 Thymidylate synthase (human) Inhibitor Methotrexate, pemetrexed Phosphofructokinase Inhibitor Antimony compounds mtor Inhibitor Rapamycin Haem polymerase (Plasmodium) Inhibitor Quinoline antimalarials 1,3-β-d-glucansynthase (fungi) Inhibitor Caspofungin1 Glucosylceramide synthase Inhibitor Miglustat 8

Encimska kinetika Michaelis Mentenova enačba 9

Lineweaver-Burkova linearizacija 10

Tipi inhibicije 11

Tipi inhibicije Trajanje inhibicije: ireverzibilni (kovalentno, nekovalentno vezani) reverzibilni Struktura inhibitorjev: podobni substratu/produktu (kompetitivni inhibitorji) niso podobni substratu/produktu (nekompetitivni in alosterični inhibitorji) Mehanizmi inhibicije: kovalentni inhibitorji inhibitorji prehodnega stanja samomorilski inhibitorji 12

Kompetitivna inhibicija 13

Nekompetitivna inhibicija 15

Nekompetitivna inhibicija 16

Akompetitivna inhibicija 17

Akompetitivna inhibicija 18

Mešana inhibicija K i v v 0 i I 1 1 S K m 19

Kompetitivna inhibicija Tetrahidrofolna kislina metotrexat 22

Kovalentna vezava 23

Analogi prehodnega stanja (transition state analogs) 26

Primeri delovanja izbranih encimskih inhibitorjev Zaviralci serinskih proteaz (trombin, faktor VIIa) Zaviralci protein kinaz Zaviralci nevramidaz 27

Literatura predavanj Foye s Principles of Medicinal Chemistry: 5. poglavje (str. 99 114). Drug Discovery Through Enzyme Inhibition Medicinal Chemistry An Intorduction (Thomas): 9. poglavje (str. 291 334). Enzymes 28