分子生物學(xué)理論課

1、The Functions of ProteinsSickle Cell Anemia (鐮刀形紅細(xì)胞貧血)N-Val His Leu Thr Pro Glu Glu C(146) HbS peptideHbA peptideN-Val His Leu Thr Pro Val Glu C(146) Protein FunctionsEnzymes (酶): substrate binding, side chain in catalysisRegulatory factors (調(diào)節(jié)蛋白): insulin, growth factorsReceptors (受體)Signaling prot

2、eins (信號分子): adapter proteinsStructural proteins (結(jié)構(gòu)蛋白): collagen, keratinMotor proteins (運(yùn)動蛋白): actin, myosin and tubulinTransport proteins (轉(zhuǎn)運(yùn)蛋白): hemoglobinImmunoglobulin or Antibodies (抗體)Storage rpoteins (儲存蛋白): casein and ovalbuminOthers Protein Classification by FunctionsEnzymesAn enzyme can

3、accelerate a reaction is because it can lower the energy barrier (activation energy) The exact mechanism of lowering the energy barrier depends on individual systems An enzyme does not change the Equilibrium Constant KAB+Ck1=10-4/sk2=10-6/sK=k1/k2=100Enzyme ClassificationOxidoreductases 氧化還原酶: 2A.2H

4、+O2=2A+2H2OTransferases 轉(zhuǎn)移酶: A.X+B=A+B.X Acetyltransferase, methylase, protein kinase and polymeraseHydrolases 水解酶: A-B+H2O=AOH+BH Proteases, Nucleases, PhosphataseLyases 裂合酶: A.B=A+BIsomerases 異構(gòu)酶: A=BLigases 連接酶: A+B+ATP=A.B+ADP+PiRegulatory Factors: InsulinReceptorsGPCRsRTKs(G protein-coupled rec

5、eptors)(Receptor tyrosine kinases)Intracellular Signaling PathwaysProtein kinasesProtein phosphataseThe phosphorylation cascade is the key for intracellular cell signalingMediated by protein kinases and phosphataseActivation of protein kinase A (PKA)GPCR (G Protein Coupled Receptor) Signalling Pathw

6、ayMotor Proteins: Muscle ContractionMolecular Components of a SacromereStructural Proteins: CollagenTransport Proteins: Myoglobin & HemoglobinMyoglobin (肌紅蛋白)Hemoglobin (血紅蛋白)The sigmoidal shape of hemoglobins oxygen-dissociation curve results from cooperative binding of oxygen to hemoglobinThis cha

7、racteristic of hemoglobin facilitates both the association and dissociation of oxygen with itCooperativity (協(xié)同效應(yīng)) When a substrate binds to the active site of one enzymatic subunit, the rest of the subunits e active/inactivePositive cooperativity (正協(xié)同效應(yīng)) or negative cooperativity (負(fù)協(xié)同效應(yīng)) Antibodies:

8、 Structure and FunctionActivation of complement 活化補(bǔ)體系統(tǒng) Activation of effector cells 活化效應(yīng)細(xì)胞Immunohistochemistry (IHC) 免疫組化& Immunofluorescence (IF) 免疫熒光IHC Staining of Human Angiogenin in Prostate Tissue SamplesProstate tissue samples from normal (A), BPH (B), and cancer (C) patients were stained wit

9、h ANG antibody. (A) normal prostate tissue. (B) BPH and (C) prostate cancer tissues. Enzyme-Linked Immunosorbent Assay (ELISA) 酶聯(lián)免疫吸附試驗(yàn)1) Obtain protein sample2) SDSProcedures of Immunoblotting:3) Transfer proteins from gel to nitrocellulose membrane using electrical current.ApplicationsTo detect if

10、 a specific protein of interest is present in a sampleTo compare the amounts of a protein of interest among different samplesTo detect the modification state of the proteinQuizUsing 2D gel separation, we found that protein A (number 3203) is upregulated in breast cancer tissue. Protein A is totally new and there are no reports for this gene. We only know the mRNA information of this gene. Please design an experiment to detect the localization of endogenous protein A in b