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Li S.,University of Miami | Micic M.,MP Biomedicals LLC | Micic M.,University of California at Irvine | Orbulescu J.,MP Biomedicals LLC | And 2 more authors.
Journal of the Royal Society Interface | Year: 2012

Human islet amyloid polypeptide (hIAPP) is the source of the major component of the amyloid deposits found in the islets of Langerhans of around 95 per cent type 2 diabetic patients. The formation of aggregates and mature fibrils is thought to be responsible for the dysfunction and death of the insulin-producing pancreatic β-cells. Investigation on the conformation, orientation and self-assembly of the hIAPP at time zero could be beneficial for our understanding of its stability and aggregation process. To obtain these insights, the hIAPP at time zero was studied at the air-aqueous interface using the Langmuir monolayer technique. The properties of the hIAPP Langmuir monolayer at the air-aqueous interface on a NaCl subphase with pH 2.0, 5.6 and 9.0 were examined by surface pressure- and potential-area isotherms, UV-Vis absorption, fluorescence spectroscopy and Brewster angle microscopy. The conformational and orientational changes of the hIAPP Langmuir monolayer under different surface pressures were characterized by p-polarized infrared-reflection absorption spectroscopy, and the results did not show any prominent changes of conformation or orientation. The predominant secondary structure of the hIAPP at the air-aqueous interface was α-helix conformation, with a parallel orientation to the interface during compression. These results showed that the hIAPP Langmuir monolayer at the air-aqueous interface was stable, and no aggregate or domain of the hIAPP at the air-aqueous interface was observed during the time of experiments. © 2012 The Royal Society.


Liu W.,University of Miami | Johnson S.,University of Miami | Micic M.,MP Biomedicals LLC | Micic M.,University of California at Irvine | And 4 more authors.
Langmuir | Year: 2012

The human insulin (HI) Langmuir monolayer at the air-water interface was systematically investigated in the presence and absence of Zn(II) ions in the subphase. HI samples were dissolved in acidic (pH 2) and basic (pH 9) aqueous solutions and then spread at the air-water interface. Spectroscopic data of aqueous solutions of HI show a difference in HI conformation at different pH values. Moreover, the dynamics of the insulin protein showed a dependence on the concentration of Zn(II) ions. In the absence of Zn(II) ions in the subphase, the acidic and basic solutions showed similar behavior at the air-water interface. In the presence of Zn(II) ions in the subphase, the surface pressure-area and surface potential-area isotherms suggest that HI may aggregate at the air-water interface. It was observed that increasing the concentration of Zn(II) ions in the acidic (pH 2) aqueous solution of HI led to an increase of the area at a specific surface pressure. It was also seen that the conformation of HI in the basic (pH 9) medium had a reverse effect (decrease in the surface area) with the increase of the concentration of Zn(II) ions in solution. From the compression-decompression cycles we can conclude that the aggregated HI film at air-water interface is not stable and tends to restore a monolayer of monomers. These results were confirmed from UV-vis and fluorescence spectroscopy analysis. Infrared reflection-absorption and circular dichroism spectroscopy techniques were used to determine the secondary structure and orientation changes of HI by zinc ions. Generally, the aggregation process leads to a conformation change from ?-helix to β-strand and β-turn, and at the air-water interface, the aggregation process was likewise seen to induce specific orientations for HI in the acidic and basic media. A proposed surface orientation model is presented here as an explanation to the experimental data, shedding light for further research on the behavior of insulin as a Langmuir monolayer. © 2012 American Chemical Society.


Li S.,University of Miami | Mulloor J.J.,University of Miami | Wang L.,University of Miami | Ji Y.,University of Miami | And 5 more authors.
ACS Applied Materials and Interfaces | Year: 2014

Biosensing methods and devices using graphene oxide (GO) have recently been explored for detection and quantification of specific biomolecules from body fluid samples, such as saliva, milk, urine, and serum. For a practical diagnostics application, any sensing system must show an absence of nonselective detection of abundant proteins in the fluid matrix. Because lysozyme is an abundant protein in these body fluids (e.g., around 21.4 and 7 μg/mL of lysozyme is found in human milk and saliva from healthy individuals, and more than 15 or even 100 μg/mL in patients suffering from leukemia, renal disease, and sarcoidosis), it may interfere with detections and quantification if it has strong interaction with GO. Therefore, one fundamental question that needs to be addressed before any development of GO based diagnostics method is how GO interacts with lysozyme. In this study, GO has demonstrated a strong interaction with lysozyme. This interaction is so strong that we are able to subsequently eliminate and separate lysozyme from aqueous solution onto the surface of GO. Furthermore, the strong electrostatic interaction also renders the selective adsorption of lysozyme on GO from a mixture of binary and ternary proteins. This selectivity is confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), fluorescence spectroscopy, and UV-vis absorption spectroscopy. © 2014 American Chemical Society.


Thakur G.,University of Miami | Pao C.,University of Miami | Micic M.,MP Biomedicals LLC | Micic M.,University of California at Irvine | And 2 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2011

Lipid rafts being rich in cholesterol and sphingolipids are considered to provide ordered lipid environment in the neuronal membranes, where it is hypothesized that the cleavage of amyloid precursor protein (APP) to Aβ (1-40) and Aβ (1-42) takes place. It is highly likely that the interaction of lipid raft components like cholesterol, sphingomylein or GM1 leads to nucleation of Aβ and results in aggregation or accumulation of amyloid plaques. One has investigated surface pressure-area isotherms of the lipid raft and Aβ (1-40) Langmuir monolayer. The compression-decompression cycles and the stability of the lipid raft Langmuir monolayer are crucial parameters for the investigation of interaction of Aβ (1-40) with the lipid raft Langmuir monolayer. It was revealed that GM1 provides instability to the lipid raft Langmuir monolayer. Adsorption of Aβ (1-40) onto the lipid raft Langmuir monolayer containing neutral (POPC) or negatively charged phospholipid (DPPG) was examined. The adsorption isotherms revealed that the concentration of cholesterol was important for adsorption of Aβ (1-40) onto the lipid raft Langmuir monolayer containing POPC whereas for the lipid raft Langmuir monolayer containing DPPG:cholesterol or GM1 did not play any role. In situ UV-vis absorption spectroscopy supported the interpretation of results for the adsorption isotherms. © 2011 Elsevier B.V.


Orbulescu J.,University of Miami | Micic M.,MP Biomedicals LLC | Micic M.,University of California at Irvine | Ensor M.,University of Kentucky | And 3 more authors.
Langmuir | Year: 2010

Human cardiac troponin I (cTnI) is the preferred biomarker in the assessment of myocardial infarction. It is known to interact with troponin C and T to form a trimeric complex. Whereas small amounts are found in the cytoplasm, most of cTnI is in the form of a complex with actin located in myofilaments. To understand these interactions of cTnI better, we first investigated the surface chemistry of cTnI as a Langmuir monolayer spread at the air-water interface. We investigated the optimal conditions for obtaining a stable Langmuir monolayer in terms of changing the ionic strength of the subphase using different concentrations of potassium chloride. Monolayer stability was investigated by compressing the cTnI monolayer to a specific surface pressure and keeping the surface pressure constant while measuring the decrease in the molecular area as a function of time. Aggregation and/or domain formation was investigated by using compression-decompression cycles, in situ UV-vis spectroscopy, Brewster angle microscopy (BAM), and epifluorescence microscopy. To ensure that the secondary structure is maintained, we used infrared reflection-absorption spectroscopy (IRRAS) directly at the air-subphase interface. It was found that cTnI forms a very stable monolayer (after more that 5000 s) that does not aggregate at the air-subphase interface. The cTnI molecules maintain their secondary structure and, on the basis of the low reflectivity observed, using BAM measurements and the low reflection-absorption intensities measured with IRRAS spectroscopy, lie flat on the subphase with the α-helices parallel to the air-subphase interface. © 2009 American Chemical Society.


Crawford N.F.,University of Miami | Micic M.,MP Biomedicals LLC | Micic M.,Cerritos College | Orbulescu J.,MP Biomedicals LLC | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2015

The changes of interfacial properties of β-galactosidase introduced into different pH environments are investigated through surface chemistry and in situ spectroscopy. Conditions for an optimal Langmuir monolayer formation were firstly obtained by varying the subphase salt concentration and the surface-pressure area isotherm was used to extrapolate the limiting molecular area of the enzyme monolayer to be around 42,000Å2molecule-1. Surface pressure stability measurements held at 20mN/m for 90min along with compression-decompression cycles revealed no aggregate formation at the air-water interface. Consistent with the data obtained from the isotherm, in situ UV-Vis and fluorescence spectroscopy shows a steep rise in absorbance and photoluminescence intensity correlating to with a switch from a liquid-expanded to a liquid-condensed phase. A decrease in subphase pH increased the electrostatic repulsion as the enzyme was protonated, leading to an expanded monolayer. Infrared absorption-reflection spectroscopy demonstrates that the enzyme adopts mainly β-sheet conformation at the air-water interface before and during the compression. © 2015 Elsevier Inc.


Trademark
Mp Biomedicals Llc | Date: 2010-07-20

Process kit used in scientific research laboratories to purify nucleic acids, the kit consisting primarily of a solution of sodium iodide, sodium chloride, and a suspension of silica in water; process kit used in medical laboratories to purify nucleic acids, the kit consisting primarily of a solution of sodium iodide, sodium chloride, and a suspension of silica in water.


Trademark
Mp Biomedicals Llc | Date: 2011-02-08

Scientific and laboratory apparatus for use in shaking vessels with a reciprocating motion.


Trademark
Mp Biomedicals Llc | Date: 2010-06-22

Scientific and laboratory apparatus for use in shaking vessels with a reciprocating motion.


News Article | November 23, 2016
Site: www.newsmaker.com.au

Industry from many centuries has utilized natural resources in the manufacturing of products that we use in our Daily lives. As the industry has expanded and brought in technological innovations, so have the different types of natural resources evolved in the process of manufacturing. Molecules derived from natural sources have become an important part of manufacturing process all over the globe. One of those widely used molecules are enzymes. From wine making to detergent manufacturing, enzymes have been used in myriad applications. One of the most widely used enzymes all over the globe is Cellulase. Cellulase is a group of enzymes that helps in the breakdown of the cellulose into smaller carbohydrates. The term Cellulase is also used to describe a mixture of enzymes working together to break down cellulose. Cellulase applications are not just limited to the healthcare and food and beverage industry. Industrial sector has widely adopted cellulase due to its catalyzing effect in cellulolysis Based on the Source, the Cellulasemarket is segmented into: Based on end use, the Cellulasemarket is segmented into: Cellulase is widely used in the processing of coffee, especially during the process of drying. Cellulase is also utilized in wine making due to its cellulolytic properties. Cellulase breaks down the skin of the grape and along with it removes tannins and the unpleasant aroma. Cellulase synergistically with other enzymes are also used to make fruit juices. With the exponential growth in the food and beverage industry, we can expect the cellulase market to grow at a healthy CAGR throughout our forecasted period of 2016-2026. Cellulase is also used in industrial applications to produce laundry detergents, cleaning and washing agents. With the burgeoning rise in the industrial sector, cellulase market is bound to witness an exponential growth throughut our forecasted period of 2016-2026. Cellulase is being recognized as an alternative to anti-biotic in the treatment of biofilms produced by Pseudomonas. With the double digit growth in the global healthcare industry and the struggle against anti-biotic resistant bacteria, we can expect the cellulase market to witness a healthy CAGR throughout our forecast period. Cellulase is also used in the burgeoning paper and pulp industry. The restraints for the cellulase market are that its production is quite costly. In terms of geography, the cellulase market has been divided in to five key regions; North America, Latin America, Europe, Asia-Pacific and Middle East & Africa. The cellulase market is expected to exhibit an above average CAGR during the forecast period. Asia Pacific region is expected to witness a high demand for cellulase over the forecasted period. Highest growth is expected to be seen specifically from India and China. Significant growth will also be witness in Middle East and Africa, Eastern Europe and Latin America. Some of the key players in the cellulase market are Worthington Biochemical Corporation, MP Biomedicals LLC, Sigma-Aldrich Co. LLC, Prozmix LLC, Creative Enzymes, bioWORLD, Amano enzyme U.S.A., Amano Enzyme Inc., Zhongbei Bio-Chem Industry Co., Ltd., Hunan Hong Ying Biotech Co., Ltd.

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