BIOL 541 1st Edition Lecture 16 Outline of Last Lecture I. TCA Outline of Current Lecture II.ETC pumpIII. Assumptions and inhibitorsIV. Regulation of UCP1 and ETCCurrent LectureBiochem lecture 16- ETC and regulation:ETC:The matrix is alkaline and the intramembrane space is acidic. ATP synthase powers the turbine engine: induces rotation of the C ring which powers the rotor. Here, mechanical energy is converted to chemical energy. 1 alpha beta pair is considered. F1 of ATP synthase consists 3 ATP synthase: each 1 alpha beta as dimmer. 3 different conformations:Dome of the gamma induces L conformation which binds ADP + Pi. Therefore, rotor spins powered by ring which is powered by H ions. Counter clockwise way, cone is up most, T conformation is induced and ADP + Pi are forced together to form ATP. Square up most and induces O conformation and releases newly formed ATP.3 dimers and 3 phases of rotation, entire 3 ring surface and 1 each one in different phase. L- conformation ADP enters. T conformation ATP forms. Cone up most ADP + Pi converted to ATP. Square moves to O conformation and ATP released. O conformation is empty, dome rotates and new substrate received in L conformation. Square moves up, O conformation and ATP released. Dome moves, L conformation enables new substrate to enter. Triangle moves and T conformation forces ADP + Pi together to form ATP. Rotation velocity is 1 and ¼ turn/ milliseconds, generating 3.7 ATP / milliseconds or3700 ATP/ second.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.This is reversible. Hydrolysis of ATP induces rotation and that’s how flagella works. Flagella have at the base a variant of ATP synthase, hydrolysis of ATP powers the flagella. Mitochondria have IF1 that inhibits hydrolysis of ATP for ATP synthesis in mitochondria.NADH + H Complex I 3 stations 3 ATPFADH + H past Complex I 2 stations 2 ATPAssumptions:Pyruvate is converted to acetyl COA in TCA and happens in mitochondria. Glycolysis is in the cytoplasm. Thereby H has to be go across the inner membrane of mitochondria for ETC. Assuming these H use malate aspartate shuttle NADH to NAD and no loss of H. Whereas Glycerol phosphate shuttle, FADH favored. In other words, 2 fewer NAD and 2 more FAD :NAD 8x3=24FAD 4x2=8 36 ATP formed dependent upon the shuttle used.A number of inhibitors are used to study ETC:ATP synthase oligomycin (antibiotic) which binds to stalk and inhibits H.Uncouplers 2,4 dinitro phenol which is hydrophobic and dissolves in the inner space.Intramembrane is acidic and uncouplers by Brownian motion couplers reach surface and becomes protonated and reaches matrix (alkaline), H dissociates. H carried back across membrane causing short circuiting. This was how weight loss drugs worked in past as energy loss causes no fat synthesis. Side effect of the drug is that as energy can be neither created nor destroyed (Law of Thermodynamics), so heat is generated in blood as fever induced form.Complex I amytalComplex III antimycin AComplex IV Cyanide CNAzide N3 (preservative in vaccines and now not in vaccines) COOur body produces uncoupling proteins to short circuit ETC. Uncoupling proteins involved are UCP 1. Reason for this is for generation of heat. UCP 1 is also called thermogenin. Infants are susceptible to cold,as more SA, radiate heat more and have less hair. Brown fat (has more mitochondria): UCP 1 generates heat in keeping infant warm.Regulation of UCP 1: Norepinephrine (hormone) or noradrenalin is produced during stress and cold. It binds to receptor beta 3 and couples to G protein and activates adenylate cyclase to form cAMP which activates PKA (protein kinase A). Glucagon and epinephrine both are for CAMP. PKA phosphorylates and activates lipase to remove Fatty acids from triglycerols for energy. Also, BKA, protein kinase 38 is for transcription for gene for UCP 1. UCP 1 is a port and proton channel which is inserted into the inner mitochondrial membrane. It allows H to return and not allow powering of ATP ase. UCP1 transmits the fatty acid and the carboxylic acid gets ionized. Intermembrane space is acidic with H and the carboxylic acid is protonated and becomes neutral and goes from intermembrane to the alkaline matrix where H dissociates trapping fatty acids. So, the proton gradient is dissipated.Functions of UCP 1:1. Temperature regulation in infants.2. In adults, white adipose tissue can be converted to brown fat. It is referred to as beige fat due to partial conversion. Although not generalized heat, heat is produced in selected areas such as nervous system synapses. Nerves transfer electrical signals via intercellular junctions called as gap junctions and chemical synapses. Axon of one neuron releases neurotransmitter to across the gap to next neuron. Delay in synapse for signal transfer can be rectified. By increasing the rate of diffusion, signal can be elevated by increasing temperature. This is called as thermosynapses.3. Weight control: Early in life, body sets weight scale for the rest of life and maintains this. Decrease in consumption increases the efficiency by suppressing UCP 1. Increase in consumptiondecreases efficiency by increasing UCP 1.4. UCP 2 and 3 are for reactive oxygen species where ETC consumes oxygen and by product are reactive oxygen species. If high levels of reactive oxygen species are present, they dampen the ETC.Regulation of ETC:1. Regulation by phosphorylation:PKA is elevated during fasting and favors ETC. PKA phosphorylates chaperone proteins (complex protein assemblage need help from chaperone proteins). Folding and maturation of Complex I is done by chaperones.2. Acetylation: If lots of energy is present, inhibition of Complex I occurs by acetylation. If low energy and NAD, then SIRT deacetylase removes acetylase.3. Ca stimulates the malate aspartate anti- portal, whereby NAD to mitochondria, Complex III, ATP ase also stimulated.4. NO by covalent modification binds to CYS. NO is by product of ETC where it inhibits as reactive species are formed in ETC by feedback inhibition.5. Regulation by gene induction: Steroids such as estrogen receptor (transcription factor) stimulate protein in Complex I, II, III, IV, and V (ATP ase). Estrogen is growth promoting and development and progression of breast and uterine cancer. ETC