*Running title: Isolation and Characterization of Avian Lactate Dehydrogenase
To whom correspondence should be addressed Sylvia DaoudKinze and James Proestes, Department of Biochemistry, Portland State University Professor, Portland Oregon, 97207-0751;
E-mail: sylviakinzie@gmail.com and proestoj@gmail.com
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Keywords: Lactate, Dehydrogenase, Avian, Bradford Assay, Affinity Column
Background: Lactate Dehydrogenase also known as LDH is an important NADH dependent enzyme in metabolism that catalyzes the conversion of Pyruvate to Lactate.
Results: Catalytic activity was detected from chicken breast muscle
Conclusion: Copious amount of catalytic activity was detected, indicating that
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Then the total of 51.32 grams of chicken was weighed out, cut into small pieces and placed in a blender along with 75 mL of cold extraction buffer.
Four short bursts (around 5 seconds per burst) were applied to complete the homogenization process with a ten second pause between each pulse. The homogenized tissue solution was then poured into three 50 mL centrifuge tubes, and was centrifuged at 15000 RPM for 20 minutes. The supernatant poured through two layers of cheese cloth into a 50 mL falcon tube, and the volume was recorded. Three 0.5 mL aliquots were saved.
Ammonium Sulfate Precipitation After centrifugation, the volume of each CFE was measured, and then per every mL, .39 grams of ammonium sulfate was weighed out. The CFE was then placed in a beaker that was suspended on top of ice in a larger beaker, which was placed on top of a stir plate. Over a course of 20 minutes, ammonium sulfate was added to the CFE while stirring slowly. After the completing adding all of the ammonium sulfate, solution was stirred for an addition 15 minutes. Followed by centrifugation at 15000 RPM for 20 minutes.
Purification of LDH
Dialysis of the Protien Dialysis of the salted protein was completed by a lab T.A.
Affinity Column Chromatography To separate LDH from the rest of the protein, affinity column chromatography method was used. A column with a plastic stopcock was loaded with Cibacron blue affinity matrix by adding
One gram of liver was sliced into pieces, then 10ml of homogenization buffer was added to it. The mixture of the liver and homogenization buffer was then placed into a homogenizer to make the liquid slurry. Once the slurry was made it was placed into a 50ml falcon tube to then be placed in the centrifuge. The slurry was centrifuged for 2 minutes at 2000rpm. Once the spin in the centrifuge was complete, the slurry had separated, the most dense particles to the bottom of the tube forming sediment and the lighter (liver succinate dehydrogenase enzyme) also known as the supernatant. The supernatant was extracted from the falcon tube and placed into a test tube. The tube was then kept at a low temperature, (in an ice bath) until it was required for use.
Procedure: I used a ruler, thermometer, and scale to take measurements. I used a graduated cylinder, short step pipet, scale, and ruler to determine volume and density. I used a volumetric flask, graduated pipet, pipet bulb, scale, and glass beaker to determine concentrations and densities of various dilutions.
The purpose of this experiment was to extract and purify LDH enzyme from chicken muscle tissue using a variety of techniques including homogenization, ammonium sulfate precipitation, dialysis, and affinity chromatography. Activity and Protein assay were used to track the overall amount of LDH present in the samples.
Colorimetric assay is a process of determining a concentration of a solution based on absorbance of light. The purpose of this lab is to determine if the Bradford assay is an accurate way to determine an unknown concentration of two samples of protein. The Bradford assay is done by measuring wavelength of light passing through a cuvette filled with Bradford dye and concentrations of PBS and proteins. After the cuvettes are mixed they are placed into a spectrophotometer to measure wavelength. The wavelength given will be used to plot a standard curve based on concentration (x-axis) and wavelength (y-axis). The standard curve is then used to measure an educated guess on the concentrations of unknown protein concentrations. We hypothesized that if we use the Bradford assay and colorimetric spectrophotometry we can determine an accurate concentration of two unknown concentrations of proteins. The results of this lab failed to reject our hypothesis based on accurate measurements of protein concentrations. The standard curves are drawn with a linear increasing slope. The Bradford assay is an accurate way to demine the concentration of an unknown concentration.
Me and my lab partner, obtained a mixture of a un known proportion from the instructor and then flow the guide line in our lab manual to separate the mixture by applying the separation method motioned in our lab manual pages 33-40 . In this experiment, the separation methods were decantation,
In biology, we learn a lot of information that we can use later on in life, no matter what field of study we go into. During this course, we learned about biochemistry, metabolic processes, homeostasis, molecular genetics and population dynamics. Throughout the learning process, we’ve had many questions or INTUS, which we use to expand our knowledge later on and determine the answers to those specific questions. The point of this assignment is to relate questions that we have developed on our particular topic we chose; to these five units we studied in biology.
gluconeogenesis part (form of glucose from lactate) with each turn of the cycle must be
• Lack of functional aldolase B enzyme reduces the amount of DHAP, leading to fewer phosphate groups available for use in the body; also, without aldolase B, fructose cannot enter the glycolysis process into which sugar will not be converted into usable energy for cell processes.
Molecular Cell Biology, 7th Edition, 2013, Lodish, Berk, Kaiser, Krieger, Bretscher. Ploegh, Amon, and Scott. W.H. Freeman and Company (ISBN-13: 978-1-4292-3413-9)
The purpose of this experiment is to familiarize oneself with the general procedures determining a partition coefficient at the microscale level and learn in weighing milligram quantities of materials on an electronic balance, the use of automatic pipets, the use of transfer pipet, and the use of a vortex mixer. Also, to familiarize oneself with extraction
A highly conserved gene will be used to identify a prokaryotic species isolated from the body. Fundamental lab techniques will be also explored and utilized, such as amplifying using PCR, cloning, and transforming the gene into a host cell. DNA electrophoresis and specific substrate plating will serve as analysis check points. The final product will be sequenced and compared to similar species to observe phylogenetic relationships.
Our hypothesis for this experiment was for both experiments, the more equal the ratios of yeast and glucose as well as mitochondrial
Results: Below are the answers to the given questions about the protein PDB ID: 4EEY.
Protein purification is a process that can be employed to separate a single protein from a larger starting material which may be anything from an organ to a cell. Isolating a purified protein from a larger fraction enables further analysis such as determination of amino acid sequence, potential biological function, and even evolutionary relationship. (Cuatrecasas 1970) In this experiment, the enzyme lactate dehydrogenase will be purified, this enzyme is found extensively in human cells and catalyzes the conversion of lactate to pyruvate, an essential part in energy production. LDH is a key part of anaerobic energy production especially within glycolysis in which LDH catalyzes the conversion of the reverse reaction, pyruvate to lactate, generating NAD+ from NADH, reproducing the oxidized form of the coenzyme which can be used for oxidative respiration. (Markert 1963) Due to the fact that number of purification steps correlates with the purity of the protein multiple purification techniques will be used to isolate a pure form of LDH. LDH will be isolated from a larger “cytosol” fraction collected from a homogenized rat liver in a previous fractionation exercise. Of the procedures that will be used to isolate and purify proteins from a larger fractionate are a set of techniques collectively known as chromatography. These techniques all have the same premise, in that they consist of a stationary phase, also known as the
In this experiment, a saturated calcium sulfate was already made and ready to use. 25.00 mL of this solution was then mixed with 10 mL of an ammonia buffer and 1 drop of