High Binding Ability Research Articles

High binding ability ligand controlled formation of CsPbX3 (X = Cl/Br, Br, I) perovskite nanocrystals with high quantum yields and enhanced stability.

CsPbX3 NCs with both high photoluminescence quantum yields (PLQYs) and enhanced stability have been obtained by using high binding ability ligands. As a result, the CsPbI3 NCs prepared using palmitic acid and oleylamine as ligands have high PLQY (up to 92%), and the PLQYs of CsPbX3 perovskite NCs can be sustained for one month with a slight decrease. Impressively, the presence of palmitic acid and stearic acid can dramatically improve the chemical stability of CsPbX3 NCs. Importantly, 1H NMR measurements indicate that much more palmitic acid remained on the surface of CsPbX3 NCs than oleic acid after purification using solvent, suggesting the higher binding ability of palmitic acid than oleic acid. Finally, the fabricated perovskite NCs were used as luminescent inks and phosphors of white light emitting diodes.

Investigating Membrane Material and Morphology for Development of Lateral Flow Biosensor

Development of membrane for bio–sensing applications, such as the detection of pathogens in drinking water for epidemics control has a huge global impact especially for public health. Membrane that applied in the bio–sensing devices should fulfill requirements such as high binding ability, fast lateral wicking time and low background staining. This paper explores the selection of membranes, including Nitrocellulose membrane (NC), Cellulose Acetate membrane (CA), Polyvinylidene Fluoride membrane (PVDF) and Nylon membrane for the detection of pathogens in water in the most efficient and rapid way. Membrane modification using glutaraldehyde enable the achieved of higher sensitivity of protein binding. Experimental findings (FTIR, porosity, membrane’s binding ability and lateral wicking time) verified the most suitable membrane for bio-sensing application. Among the tested membranes, NC appeared as the most suitable lateral flow membrane as its performances of high protein binding ability and fast lateral wicking time. Throughout this study, we showed the correlation of membrane’s material and morphology to its performances for pathogens detection in drinking water.

Imidazole-thiazole coupled derivatives as novel lanosterol 14-α demethylase inhibitors: ionic liquid mediated synthesis, biological evaluation and molecular docking study

A novel series of imidazole-thiazole coupled derivatives (7a–7q) were synthesized using Green protocol and identified by different spectroscopic techniques. The synthesized derivatives (7a–7q) were evaluated for their in vitro antifungal activity against the six fungi strains. The compounds 7j and 7k exhibited the most promising antifungal activity. The compound 7k exhibited extremely high antifungal activity against C. albicans, C. glabrata, F. oxysporum, A. flavus, A. niger, and C. neoformans with MIC80 values of 0.2, 0.2, 20, 35, 40, and 5 µg/ml respectively. The mode of action of the most promising antifungal compounds 7j and 7k was established by ergosterol extraction and quantitation assay. From the ergosterol extraction and quantitation assay it was found that the compounds 7j and 7k act by inhibition of ergosterol biosynthesis in C. albicans. The molecular docking study revealed the high spontaneous binding ability of the tested compounds to the active site of lanosterol 14α-demethylase, which proves that the tested compounds inhibit the synthesis of lanosterol 14α-demethylase. The synthesized compounds were analyzed for ADMET properties to establish oral drug like behavior and shows satisfactory results. To establish the antifungal selectivity and safety, the most active compounds were further tested for cytotoxicity against human cancer cell lines HeLa and K-562 and were found to be non-cytotoxic in nature. The in vivo acute oral toxicity study was performed for the most active compounds and results indicate that the compounds are non-toxic in nature.

Anion recognition with porphyrin-bottomed tetraurea receptors

Three tetraurea-appended porphyrin derivatives were synthesized and applied as anion receptors to complex with various anions, including F−, Cl−, Br−, I−, NO3−, HSO4−, and AcO−. The binding stoichiometries were all measured to be 1:1 and high binding abilities of these receptors toward the anions were demonstrated with the association constants of up to 1.1×108L/mol. The complexation of the receptors with anions was further unambiguously confirmed by single-crystal X-ray analysis

Biological Evaluation and Molecular Docking of Protocatechuic Acid from Hibiscus sabdariffa L. as a Potent Urease Inhibitor by an ESI-MS Based Method.

Studies on enzyme inhibition remain a crucial area in drug discovery since these studies have led to the discoveries of new lead compounds useful in the treatment of several diseases. In this study, protocatechuic acid (PCA), an active compound from Hibiscus sabdariffa L. has been evaluated for its inhibitory properties against jack bean urease (JBU) as well as its possible toxic effect on human gastric epithelial cells (GES-1). Anti-urease activity was evaluated by an Electrospray Ionization-Mass Spectrometry (ESI-MS) based method, while cytotoxicity was assayed by the MTT method. PCA exerted notable anti-JBU activity compared with that of acetohydroxamic acid (AHA), with IC50 values of 1.7 and 3.2 µM, respectively. PCA did not show any significant cytotoxic effect on (GES-1) cells at concentrations ranging from 1.12 to 3.12 µM. Molecular docking study revealed high spontaneous binding ability of PCA to the active site of urease. Additionally, the anti-urease activity was found to be related to the presence of hydroxyl moieties of PCA. This study presents PCA as a natural urease inhibitor, which could be used safely in the treatment of diseases caused by urease-producing bacteria.

Purification of Bovine Bone Oligophosphopeptide with High Calcium-binding Activity by <i>Bacillus cereus </i>MBL13 Collagenolytic Protease

A demineralized bovine bone was hydrolyzed by a specific bone-degrading collagenolytic protease extracted from Bacillus cereus MBL13 (isolated from chopped animal bone wastes) to utilize its collagen in nutraceuticals with high calcium bioavailability. Bovine bone peptide (BBP), a novel oligophosphopeptide with a high calcium binding ability (8.25 mmol/g-protein), was isolated from bovine bone hydrolysates by Chelex 100, ultrafiltration, hydroxyapatite chromatography, gel filtration chromatography, and reverse-phase high performance liquid chromatography. The results showed that demineralization treatment can significantly increase hydrolysis (p < 0.05). The amino acid content of BBP showed that the Asp, Ala, Tyr, and Thr contents were remarkable increments compared to the bone hydrolysates. The molecular mass of BBP was found to be around 3.305 kDa through SDS-PAGE and MALDI-TOF mass spectrometry. FT-IR spectra showed characteristic absorption peaks. Moreover, BBP exhibited higher calcium binding activity than that of casein oligophosphopeptide (CPP). Therefore, this study demonstrated that B. cereus MBL13 collagenolytic protease (BCC) could degrade bovine bone collagen, and prepared oligophosphopeptide could be utilized as a nutraceutical with high calcium-binding activity.

A fractionation approach applying chelating magnetic nanoparticles to characterize pericardial fluid's proteome

Owing to their close proximity, pericardial fluid (PF)’s proteome may mirror the pathophysiological status of the heart. Despite this diagnosis potential, the knowledge of PF's proteome is scarce. Large amounts of albumin hamper the characterization of the least abundant proteins in PF. Aiming to expand PF's proteome and to validate the technique for future applications, we have fractionated and characterized the PF, using N-(trimethoxysilylpropyl)ethylenediamine triacetic acid (EDTA)-functionalized magnetic nanoparticles (NPs@EDTA) followed by a GeLC-MS/MS approach. Similarly to an albumin-depletion kit, NPs@EDTA-based fractionation was efficient in removing albumin. Both methods displayed comparable inter-individual variability, but NPs@EDTA outperformed the former with regard to the protein dynamic range as well as to the monitoring of biological processes. Overall, 565 proteins were identified, of which 297 (>50%) have never been assigned to PF. Moreover, owing to this method's good proteome reproducibility, affordability, rapid automation and high binding ability of NP@EDTA, it bears a great potential towards future clinical application.

Design of bio-inspired silica-encapsulated protein A for improved immunoprecipitation assays

Staphylococcus aureus Protein A (SpA) has a high affinity to the Fc region of antibodies (Abs), and SpA-immobilized matrices are widely used for Ab purification or immunoprecipitation (IP) assays. Here, we employed a bio-inspired silica-encapsulation method to improve the Ab-binding ability of an SpA-immobilized matrix. Two silica-forming peptides (SFPs), namely R5 and EctP1, were separately introduced at the C-terminus of SpA to generate two recombinant fusion proteins (SpA-SFPs) with auto-silicifying abilities. When SpA-SFPs were employed as Ab-binders on a solid surface (96-well plate), they showed an effective Ab-binding ability and a better performance than intact SpA. A high binding ability was observed even when an SFP-mediated SpA silica matrix (SpA-SFP@SiO2) was prepared. SpA-SFP@SiO2 showed a higher performance than commercially obtained SpA-Agarose particles and no loss of matrices. Moreover, in IP assays, SpA-SFP@SiO2 showed an approximately 300% higher precipitation of target protein than the commercial SpA-Agarose product when a small amount of cell lysate was used. These findings demonstrated that SpA-SFP could be useful for the development of an efficient immunoassay system.

A novel variable antibody fragment dimerized by the dHLX peptide with enhanced affinity against amantadine compared to its corresponding scFv antibody

ABSTRACT Amantadine (AMA) is an illegally used antiviral drug in the poultry industry, it is necessary to establish a fast, accurate and time-saving detection method for poultry food. The antibody-based immunoassay can achieve fast and accurate requirements. We developed a recombinant antibody-based specificity immunoassay for AMA. In the recombinant antibody, the heavy chain variable region (VH) is connected covalently with the light chain variable region (VL) by the artificial linker. Here, two recombinant antibodies’ single-chain variable fragment (scFv) and scFv-dHLX were constructed and functionally expressed in the periplasm of Escherichia coli. The helix-turn-helix peptide was utilized to dimerize VH and VL similar to the IgG counterpart. The ScFv-dHLX protein showed a higher binding ability and affinity resulting in improvement of in vitro affinity activity over its corresponding scFv. Our results not only indicated scFv-dHLX as an alternative for scFv in analytical application, but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced affinity.

Li-O2 Cell with LiI(3-hydroxypropionitrile)2 as a Redox Mediator: Insight into the Working Mechanism of I- during Charge in Anhydrous Systems.

Redox mediators (RMs) have been widely applied to reduce the charge overpotential of nonaqueous lithium-oxygen (Li-O2) batteries. Among the reported RMs, LiI is under hot debate with lots of controversial reports. However, there is a limited understanding of the charge mechanism of I- in anhydrous Li-O2 batteries. Here, we study the chemical reactivity between the oxidized state of I- and Li2O2. We confirm that the Li2O2 particles could be chemically oxidized by I2 rather than I3- species. Furthermore, our work demonstrates that the generated I- from Li2O2 oxidation would combine with I2 to give I3- species, hindering further oxidation of Li2O2 by I2. To improve the working efficiency of I- RMs, we introduce a compound LiI(3-hydroxypropionitrile)2 (LiI(HPN)2) with a high binding ability of I-. Compared with LiI, the cell that contained LiI(HPN)2 shows a significantly increased amount of I2 species during charge and enhanced Li2O2 oxidation efficiency under the same working conditions.

Immunological evaluation of some antigens of Lucilia sericata larvae.

The present study aimed to select an antigen of Lucilia sericata larvae showing both high antigenicity and cross-reactive binding abilities with other related antigens of L. sericata larvae for obtaining a promising candidate vaccine antigen. The ELISA results primary concluded that among the excretory secretory (ES) and midgut (MG) antigens of the different larval instars of L. sericata, MGL2 could be characterized as antigen which was able to reflect the highest level of antigenicity and cross-reactivity with the other tested L. sericata antigens. The results were extended to spot the light on the relation between different protein bands in MGL2 and rabbit hyper- immune sera (HIS) raised against the other tested antigens using SDS-PAGE and Western blot technique. Analysis by SDS-PAGE of ES and MG antigens of the different larval instars of L. sericata revealed common protein bands at molecular weights of about 10, 12, 16, 20, 28, 33 and 46kDa. Western blotting of MGL2 antigen transferred to nitrocellulose sheet revealed reaction by MGL2 HIS to five polypeptide bands; 20, 28, 33, 46 and 63kDa. Three bands of 28, 33 and 63kDa were the most prominent bands detected whereas; there was a weak reaction with bands of 20 and 46kDa. But what was apparent in Western blot was a strong reaction of all tested HIS with a polypeptide band of 63kDa. This band might be considered to be the main cause of cross reactive binding ability of MGL2 antigen that had been recorded previously in ELISA technique.

Virtual Screening of Drugs against HIV-1 Protease

The life-threatening infections and pandemic spread of Human Immunodeficiency virus-1 (HIV-1), the etiologic agent of AIDS, has promoted an unending scientific effort to understand and control the disease. The resultant understanding of HIV-1 life cycle has defined many different targets for potential drug intervention. HIV protease enzyme responsible for cleaving large polyprotein precursors into biologically active protein products is an important target for the treatment of AIDS. However drug resistance is a persistent problem and new protease inhibitors are needed. Tipranavir, one of the protease inhibitors most recently approved for clinical use has been shown to be potent against viruses harbouring multidrug resistance mutations such as V82A and L90M, but even this drug is shown to lose potency due to certain mutations or mutation patterns. Thus 10 derivatives of the drug Tipranavir, chemically diverse from the initial hit were generated and screened to determine their ability to interact with protease. Further analysis revealed one unique compound with high binding ability from the initial hit and its possibility for new class of protease inhibitors is discussed in this report.

Abstract 5885: Sialyl Lewis X-P-selectin connection between ovarian tumor-mesothelium in early stage metastasis

Abstract Metastasis is one of the major challenges for the treatment of ovarian cancer. Unlike other solid tumors, ovarian cancer primarily disseminates within the peritoneal cavity. A crucial step in metastasis formation is the adhesion of ovarian cancer cells onto the peritoneal mesothelium under ascitic shear flow. However, the adhesion mechanisms engaged in this tumor-mesothelium interaction remain elusive due to a lack of physiologically relevant model to manipulate and investigate this dynamic process. In this study, using a 3D microfluidic platform, we found that the metastatic population of cancer stem cells (M-CSCs) exhibited slower rolling velocity and higher binding ability to the peritoneal mesothelium than non-metastatic (NM)-CSCs under flow condition. This adhesion cascade was mediated by P-selectin which expressed on the peritoneal mesothelium. The key carbohydrate determinant on M-CSCs was a glycoprotein, but not a glycolipid, with its recognition as sialyl-Lewis X (sLeX) in a sialic acid- and fucose-dependent manner. Moreover, several glycosyltransferase genes including B4GALT4, ST3GAL3, ST3GAL4 and FUT-5 involved the synthesis of sLeX were upregulated in M-CSCs. Knocking down FUT-5 significantly inhibited ovarian tumor cell adhesion on the mesothelium in vitro and reduced the metastatic potential in vivo. Taken together, our findings revealed that a distinct sLeX-P-selectin axis of ovarian tumor-mesothelium interaction in early metastasis and may offer the possibility of new therapeutic targets. (This work is supported by RGC grant 17122014) Citation Format: Shan-Shan Li, Carman K. M. Ip, Ayon A. Hassan, Matthew Y. H. Tang, Susan Yung, Tak-Mao Chan, Ho Cheung Shum, Alice S. T. Wong. Sialyl Lewis X-P-selectin connection between ovarian tumor-mesothelium in early stage metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5885. doi:10.1158/1538-7445.AM2017-5885

99mTc-LHRH in tumor receptor imaging.

Detection of gonadotropin-releasing hormone (GnRH) also known as luteinizing hormone-releasing hormone (LHRH) in the relevant tumor tissue and normal tissues and organs in vivo expression was investigated. To examine the method of direct radio labeling of LHRH by 99mTc with relatively high radiochemical purity and stability, screening the best labeling conditions, to establish a simple and reliable method of preparation of 99mTc-LHRH was undertaken. The detection of radioisotope-labeled LHRH distribution in mice, LHRH receptor imaging for the study and treatment of cancer basis were evaluated. i) Immunohistochemical staining test was used in 23 patients with hepatocellular carcinoma (HCC), 20 patients with breast cancer, 10 patients with prostate cancer, 20 patients with lung cancer, 20 patients with endometrial cancer tumor cells and normal tissue LHRH-R De Biaoda levels; ii) pre-tin method use direct labeling of LHRH, marking completion of saline or human serum were added at room temperature, the chromatography was measured at different times, to calculate the rate of labeled product and the radiochemical purity of the label, in vivo observation of its stability, and comparative analysis of selected optimal condition; iii) rat pituitary cell membrane protein, the product of in vitro radio-receptor marker analysis, through the saturation and inhibition experiments, was used to test its receptor binding activity; iv) Ch-T method labeled 125I-LHRH, tail vein injection of normal mice at different times were sacrificed, blood and major organs were determined and calculated per gram organization percentage injected dose rate (%, ID/g). Detected by immunohistochemistry in 23 cases of HCC in the LHRH-positive rate was 82.61%, in the corresponding normal tissues, the positive rate was 15%; 20 cases of breast cancer positive rate of 95%, the corresponding normal tissues, the positive rate was 20%; 10 cases of prostate cancer positive rate of 70%, the corresponding normal tissues, the positive rate of 40%; 20 cases of lung cancer positive rate of 85%, the corresponding normal tissues, the positive rate of 15.79%; 20 cases of endometrial cancer positive rate of 80% in the corresponding normal tissues was 16.67% positive. 99mTc-LHRH mark was 97.9–100.0%, the radiochemical purity of 93.9–96.4%, marking the reaction gel content of <5%. Great product receptor marker analysis showed 99mTc-LHRH with saturable receptor binding characteristics and inhibition, and high affinity, RT = 23.2174 pmol, KD = 0.4348 nmol; intravenous injection of 131I-LHRH within 72 h after the mice rapidly cleared the blood radioactivity, the major radioactive accumulation in the liver and kidneys and by the liver, renal clearance, and other tissues and organs of the radioactivity gradually decreased with time. In conclusion, i) the liver, lung, breast, prostate, endometrial cancer exist in both LHRHR; ii) 99mTc-LHRH preparation is simple, rapid, radiochemical purity product obtained higher marks, better stability, no further purification; and iii) LHRH 99mTc labeled, still has a high receptor binding ability, biological activity; and has an ideal and realistic dynamics in animals, there is hope, as with the clinical value of imaging agent of GnRH receptors.

Aptamer-mediated gene therapy enhanced antitumor activity against human hepatocellular carcinoma in vitro and in vivo

A recombinant adenovirus carrying the tumor suppressor gene PTEN (Ad5-PTEN) is an effective antitumor agent against liver cancer. But the application of Ad5-PTEN has been greatly hindered by its auto-immunogenicity, non-specific toxicity to normal tissues, as well as poor stability in blood stream because of neutralizing antibody. Epithelial cell adhesion molecule (EpCAM) is over-expressed in most solid tumors and it has been identified to be a cancer stem cell surface marker in liver cancer. An RNA aptamer EpDT3 could specially bind with EpCAM and target EpCAM-positive cells. Therefore, we hypothesized that developing a novel gene delivery system of EpDT3-modified Ad5-PTEN could overcome the disadvantages of naked Ad5-PTEN and enhance the antitumor effect on hepatocellular carcinoma. We took polyethylene glycol (PEG) as a linker to conjugate EpDT3 with Ad5-PTEN to prepare EpDT3-PEG-Ad5-PTEN (EPAP) by simple chemical synthesis method. We found that the stability of this novel gene delivery system in human blood serum increased about 16-fold compared to the naked adenovirus. Meanwhile, EPAP enhanced gene expression and cellular uptake in HepG2 cells, and showed significant inhibition in cell proliferation and cell migration against hepatocellular carcinoma cells HepG2 while showing no cytotoxicity to normal liver cells L-02, compared with Ad5-PTEN. Importantly, EPAP could induce cell apoptosis and presented superior antitumor activity against aggressive HepG2 xenograft in nude mice but showed no obvious toxicity to the tested mice at the therapy concentration. In conclusion, EpCAM aptamer EpDT3 could significantly enhance the antitumor effect of Ad5-PTEN with high binding ability to EpCAM-positive cells HepG2.

CdS quantum dot-chitosan-anti SP17 nanohybrid as a potential cancer biomarker

Sperm protein 17 (SP17) is selectively overexpressed in several human malignancies including ovarian carcinoma, but is absent or expressed at low levels in most normal tissues. In this research, a nanohybrid of cadmium sulphide (CdS)-chitosan-anti SP17 was developed for the first time. Chitosan was covalently conjugated with CdS-anti SP17 by using the 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (sulfo-NHS). The nanostructures were characterized by Fourier transform infrared spectroscopy (FIIR) and transmission electron microscopy (TEM). FTIR results demonstrated successful conjugation of chitosan to cadmium sulphide (CdS) quantum dots. The TEM images indicated formation of ultra-small nanocrystals with average diameters in the range of 3nm. Moreover, ELISA result showed relatively high binding ability of QDs to the Sp17 recombinant antigen, which could be potentially used for detection and imaging of cancer tumors.

Drug-protein binding mechanism of juglone for early pharmacokinetic profiling: Insights from ultrafiltration, multi-spectroscopic and molecular docking methods

Juglone (JL), as one of the major bioactive components present in the bark of Juglans mandshruica Maxim, exhibits versatile bioactivities, especially anti-cancer activity. To better understand the pharmacokinetic properties of juglone, the protein binding rate of juglone was determined by ultrafiltration method, and the binding affinity and mechanism between JL and human serum albumin (HSA) was investigated in vitro through multi-spectroscopic, thermodynamic, and molecular modeling methods. The binding degree of JL was measured more than 99.0% which suggested that JL had high binding ability to serum albumin. Fluorescence data showed that juglone quench the intrinsic fluorescence of HSA upon forming the JL–HSA nonfluorescent complex at 1:1 stoichiometric proportion, and the complex formation had a high affinity of 104 L·mol−1. Meanwhile, the site marker competitive experiments and the thermodynamic parameters (ΔG=-26.08 kJ·mol−1, ΔH=–16.34 kJ·mol−1, ΔS=32.69 J·mol−1·K−1) indicated that juglone could spontaneously bound to the site I (subdomain IIA) of HAS through hydrophobic and hydrogen bonding interactions. As further revealed by the synchronous fluorescence, three-dimensional fluorescence, Fourier transform infrared (FT-IR) and circular dichroism (CD) spectroscopy, JL could cause conformational and structural alterations of HSA. Additionally, molecular docking was employed to further define the specific binding site and the result was in accordance with the conclusion of experimental analysis. The present work provided reasonable models helping us further understand the pharmacokinetics, pharmacological and toxic effects of JL in vivo and supplied an important insight for the applications of JL in the clinical research.

Intrinsic Ultrahigh Drug/miRNA Loading Capacity of Biodegradable Bioactive Glass Nanoparticles toward Highly Efficient Pharmaceutical Delivery.

The lack of safe and efficient drug and gene delivery vectors has become a major obstacle for the clinical applications of drug and nonviral gene therapy. To date, for nonviral gene vectors, most studies are focused on cationic polymers, liposomes, and modified inorganic nanoparticles which have shown high cellular toxicity, low transfection efficiency, or nondegradation. Additionally, few biodegradable biomaterials demonstrate intrinsic high binding abilities to both drug and gene. Bioactive glasses (BGs) have achieved successful applications in bone regeneration due to their high biocompatibility and biodegradation. Here, for the first time, we demonstrate the intrinsic ultrahigh drug and miRNA binding ability of bioactive glass nanoparticles (BGNs) without any cationic polymer modification. BGNs demonstrate an over 45-fold improvement in hydrophilic drug loading (diclofenac sodium) and 7-fold enhancement in miRNA binding over their corresponding silica nanoparticles. The hydrophilic drug loading ability of BGNs (>45 wt % loading) is also higher than that of most other reported inorganic nanoparticles, including mesoporous silica nanoparticles. BGNs show significantly lower cytotoxicity and higher cellular uptake and miRNA transfection efficiency compared to those of commercial transfection reagents polyethylenimine and lipofectamine 3000. Our results demonstrate that BGNs may become a new competitive vehicle for drug and gene delivery applications. This study may also provide a new strategy to develop novel biomaterials with intrinsic drug and gene binding ability for disease therapy.

Effects of nano-CaCO3 on the adsorption of carboxymethyl starch onto magnetite concentrate in pelletizing

The carboxylmethyl starch modified with nano-CaCO3 has been identified as an alternative binder in iron ore pelletization. This study aims to further clarify effects of nano-CaCO3 on the adsorption of carboxymethyl starch (CMS) onto magnetite particles. Variables influencing the adsorption capacity of CMS, such as solution pH, initial concentration, the ratio of nano-CaCO3 to CMS and adsorption time, were systematically investigated. Zeta potential and solution pH results verify that nano-CaCO3 can serve as an active site, which reducing the repulsive force between the negatively charged CMS and magnetite surface. Consequently, the adsorption capacity of CMS is promoted by the addition of nano-CaCO3. Besides, both the adsorption capacity of CMS and strengths of green pellets with the addition of nano-CaCO3 decrease by increasing the pH value of binder solution. In other words, there is a positive correction between the adsorption capacity and the strength of green pellet. The equilibrium adsorption data of CMS can be described by the Freundlich isotherm. The addition of nao-CaCO3 does not change the adsorption type of CMS onto magnetite surface. For the adsorption of CMS with or without the addition of nano-CaCO3, the pseudo-second-order kinetics of chemical reaction provides the best correlation. Moreover, the adsorption rate of CMS with nano-CaCO3 is much larger than that of CMS. SEM results indicate that the cross-linked structure built by CMS+nano-CaCO3 is unique and different from that of CMS. The nano-CaCO3 can serve as the active site and skeleton, and promote the cohesion force of neighboring CMS molecules. Consequently, this unique structure gives CMS+nano-CaCO3 a high binding ability.

Galactose-binding lectin from mulberry ( Morus alba L.) seeds with growth hormone-like activity

Abstract Plant lectins are well documented to participate in multiple physiological activities based on selective binding to the carbohydrate structures. They have been reported to play significant roles in various processes such as growth and development, differentiation and plant protection. Nevertheless, the intrinsic roles of plant lectins still remain undefined. We purified a galactose-binding lectin, named MAL, from mulberry (M. alba L.) seeds and analyzed its properties. The lectin is composed of one polypeptide of 17 kDa, which is abundant in the seed protein fraction. MAL interacted with GalNAc and galactose residues of saccharides with high binding ability. Western blotting analysis suggested that MAL is deposited in the mulberry leaves and inflorescence. MAL was examined for growth stimulatory activity on mulberry hypocotyls and internodal sections of in vitro grown P. euphratica cultures. Elongation of mulberry hypocotyls was detected in the apical parts of the hypocotyl, where the growth increment was 58%. MAL had no significant effect on the stem elongation and induction of new leaves. Our results suggest that MAL may be involved in the growth and cell elongation at initial stages of tissue development.