Recent advances towards single biomolecule level understanding of protein adsorption phenomena unique to nanoscale polymer surfaces with chemical variations

Protein adsorption onto polymer surfaces is a very complex and ubiquitous phenomenon whose integrated process impacts essential applications in our daily lives such as food packaging materials, health devices, diagnostic tools, and medical products. Increasingly, novel polymer materials with greater chemical intricacy and reduced dimensionality are used for various applications involving adsorbed proteins on their surfaces. Hence, the nature of protein-surface interactions to consider is becoming much more complicated than before. A large body of literature exists for protein adsorption. However, most of these investigations have focused on collectively measured, ensemble-averaged protein behaviors that occur on macroscale and chemically unvarying polymer surfaces instead of direct measurements at the single protein or sub-protein level. In addition, interrogations of protein-polymer adsorption boundaries in these studies were typically carried out by indirect methods, whose insights may not be suitably applied for explaining individual protein adsorption processes occurring onto nanostructured, chemically varying polymer surfaces. Therefore, an important gap in our knowledge still exists that needs to be systematically addressed via direct measurement means at the single protein and sub-protein level. Such efforts will require multifaceted experimental and theoretical approaches that can probe multilength scales of protein adsorption, while encompassing both single proteins and their collective ensemble behaviors at the length scale spanning from the nanoscopic all the way to the macroscopic scale. In this review, key research achievements in nanoscale protein adsorption to date will be summarized. Specifically, protein adsorption studies involving polymer surfaces with their defining feature dimensions and associated chemical partitions comparable to the size of individual proteins will be discussed in detail. In this regard, recent works bridging the crucial knowledge gap in protein adsorption will be highlighted. New findings of intriguing protein surface assembly behaviors and adsorption kinetics unique to nanoscale polymer templates will be covered. Single protein and sub-protein level approaches to reveal unique nanoscale protein-polymer surface interactions and protein surface assembly characteristics will be also emphasized. Potential advantages of these research endeavors in laying out fundamentally guided design principles for practical product development will then be discussed. Lastly, important research areas still needed to further narrow the knowledge gap in nanoscale protein adsorption will be identified.

     

Standardization of ginseng processing for maximizing the phytonutrients of ginseng

This study was designed to optimize the process conditions, such as steaming, drying, and extracting, for obtaining the maximum content of prosapogenin (Rg3, Rg2, Rh1, and Rh2) from red ginseng, which has antitumor and anti-cancer properties. The steaming process was performed in an autoclave and the drying and extracting processes were done in dryer and heat extractor, respectively, and content of each prosapogenin was analyzed by HPLC. In the steaming process, prosapogenin values did not show any significant increase at 80 or 90°C, but tended to increase sharply as the steaming period became longer at 100°C, and the maximum value was obtained at 100°C with 6 h of steaming without any significant difference between local Gyeonggi areas. Drying red ginseng at 70°C for 24 h was the optimal condition to enhance prosapogenin extraction without affecting the quality. Maximal crude saponin and prosapogenin contents were obtained using 70% ethanol as the solvent at 70°C in the extracting process. Using these standardization processes such as steaming, drying, and extraction, maximum prosapogenin values could be obtained at ginseng factories.

     

The usefulness of Tc-99m HMPAO labeled WBC SPECT in eosinophilic gastroenteritis

Tc-99m HMPAO labeled WBC SPECT was performed in 5 patients with eosinophilic gastroenteritis before and after successful medical therapy. The imaging findings were graded according to the following imaging scheme; grade 0, no uptake; grade 1, uptake < bone marrow; grade 2, uptake < liver; grade 3, uptake > liver. In no patient was the diagnosis made radiologically or with colonoscopy. The sites of involvement were identified with Tc-99m HMPAO WBC imaging in all patients before treatment and the radionuclide imaging studies were all negative after therapy.     

Overload vector quantisation by selective shell projection inlattice VQ

An efficient overload vector quantisation algorithm is proposed for lattice vector quantisation (LVQ). It selects a projection shell for each overload vector by changing its scaled position along the radial direction to the origin in the truncated lattice and obtains the adjusted overload scaling factor for dequantisation from the orthogonality principle. Experimental results show that this algorithm achieves a good performance in signal to quantisation noise ratio (SQNR) over the conventional algorithm using a single projection of the overload vector on the external shell     

Protease Inhibitors from Plants with Antimicrobial Activity

Antimicrobial proteins (peptides) are known to play important roles in the innate host defense mechanisms of most living organisms, including plants, insects, amphibians and mammals. They are also known to possess potent antibiotic activity against bacteria, fungi, and even certain viruses. Recently, the rapid emergence of microbial pathogens that are resistant to currently available antibiotics has triggered considerable interest in the isolation and investigation of the mode of action of antimicrobial proteins (peptides). Plants produce a variety of proteins (peptides) that are involved in the defense against pathogens and invading organisms, including ribosome-inactivating proteins, lectins, protease inhibitors and antifungal peptides (proteins). Specially, the protease inhibitors can inhibit aspartic, serine and cysteine proteinases. Increased levels of trypsin and chymotrypsin inhibitors correlated with the plants resistance to the pathogen. Usually, the purification of antimicrobial proteins (peptides) with protease inhibitor activity was accomplished by salt-extraction, ultrafiltration and C₁₈ reverse phase chromatography, successfully. We discuss the relation between antimicrobial and anti-protease activity in this review. Protease inhibitors from plants potently inhibited the growth of a variety of pathogenic bacterial and fungal strains and are therefore excellent candidates for use as the lead compounds for the development of novel antimicrobial agents.     

UV photo-responsive characteristics of an n-channel GaN Schottky-barrier MISFET for UV image sensors

The ultraviolet (UV) responsive properties of the enhancement-mode n-channel Schottky-barrier MISFET (SB-MISFET), which was fabricated on a p-type GaN layer grown on silicon substrate, were investigated. The drain leakage current of the MISFET is less than 1 nA/mm/sup 2/, which is quite low compared to recently reported photodetectors. The MISFET exhibited a cutoff wavelength of 365 nm, and the UV/visible rejection ratio was about 120 near the threshold voltage. This is the first demonstration of the MISFET-type UV photodetector, which is highly applicable to the UV image sensors.     

Inhibitory effect of phosphatidylserine on atopy-like dermatitis in NC/Nga mice

In the present study, the anti-atopic effect of phosphatidylserine (PS) extracted from soybean was investigated in NC/Nga mice. The atopic symptoms were evaluated by scoring spontaneous scratching behavior and skin lesions, by measuring serum levels of immunoglobulin E (IgE) and interleukin-4 (IL-4), and by observing skin histology. After observing the maximum severity of atopic symptoms, PS was initiated. The PS treatment significantly alleviated apparent symptoms of atopic dermatitis and scratching behavior. The suppression of atopic dermatitis by PS was verified by decreases in the serum levels of IgE (p<0.05 after 8 weeks; p<0.001 after 9 weeks) and IL-4 (p<0.01 after 7 weeks; p<0.001 after 9 weeks). Histological observations also indicated that the thickening process of skin and the infiltration of inflammatory cells were significantly inhibited. Taken together, PS from soybean might be useful for alleviating atopic dermatitis symptoms and thus for developing a new medicine for treating human atopic disease.     

Characterization of traditionally fermented Korean soybean paste, eoyukjang, and isolation of its microorganisms

In this study, traditionally fermented Korean soybean paste, eoyukjang, was characterized and its microorganisms were isolated. The contents of amino-type and ammonia-type nitrogens in the pastes we examined were 89.60 to 98.93 mg/% and 0.32 to 0.30 mM, respectively. Antioxidant activity increased during ripening, with antioxidant activities in 1- and 4-year-old pastes measured at 9.80 and 13.84 μmol of Trolox equivalents/g, respectively. Twenty-two and 19 microorganisms were isolated from soybean pastes under aerobic and anaerobic conditions, respectively. After identification, Bacillus amyloliquefaciens, Bacillus subtilis, and Bacillus vallismortis were dominant. In the enzyme activities, protease and lipoxygenase activities were observed from 0.065 to 0.733 unit/mg protein and 0.016 to 0.19 unit/mg protein, respectively. Amylase activity was, however, broad between 43.1 to 571.8 unit/mg protein.