Read by QxMD icon Read

Affinity chromatography

Andrew R Swartz, Xuankuo Xu, Steven J Traylor, Zheng Jian Li, Wilfred Chen
Affinity precipitation using Z-ELP-E2 nanocages has been shown to be a promising alternative to Protein A chromatography for monoclonal antibody (mAb) purification. We have previously described a high-yielding, affinity precipitation process capable of rapidly capturing mAbs from cell culture through spontaneous, multi-valent crosslinking into large aggregates. To challenge the capabilities of this technology, nanocage affinity precipitation was investigated using four industrial mAbs (mAbs A-D) and one Fc fusion protein (Fc A) with diverse molecular properties...
April 21, 2018: Biotechnology and Bioengineering
Yujie Zhang, Qiaoqi Li, Benlin Dai, Shouyong Zhou, Mingliang Zhang, Haifeng Han, Hongdeng Qiu
A new polar-embedded aromatic stationary phase has been prepared by covalently attaching p-biphenylacetamide silane to silica spheres. The retention behavior of this phase was compared with an alkylamide counterpart and octadecyl phases using different classes of analytes, including geometric isomers and congeners from Standard Reference Materials 869b, 870 and 1647e, positional isomers of electron-deficient benzenes, as well as alkylbenzenes and alkylbiphenyls. The relationship between shape selectivity and surface chemistry of stationary phase was comparatively studied...
April 14, 2018: Journal of Chromatography. A
Chao-Wen Cheng, Che-Chang Chang, Hsiu-Wen Chen, Ching-Yu Lin, Jin-Shuen Chen
BACKGROUND: Among multiple causes, diabetic nephropathy (DN) is the major underlying renal disease that leads to end-stage renal disease (ESRD), and early diagnosis can effectively prevent or delay the progression to ESRD. Therefore, the current study aimed to develop non-invasive, accurate detection markers. MATERIALS & METHODS: For this study, 62 diabetes mellitus (DM) patients, 59 DN patients, and 21 healthy controls (HCs) were recruited. All participants' serum samples were subjected to concavanalin (Con) A affinity chromatography, which utilizes glycoproteins to discover potential markers...
April 19, 2018: European Journal of Clinical Investigation
Oscar B Torres, Alexander J Duval, Agnieszka Sulima, Joshua F G Antoline, Arthur E Jacobson, Kenner C Rice, Carl R Alving, Gary R Matyas
We describe for the first time a method that utilizes microscale thermophoresis (MST) technology to determine polyclonal antibody affinities to small molecules. Using a novel type of heterologous MST, we have accurately measured a solution-based binding affinity of serum antibodies to heroin which was previously impossible with other currently available methods. Moreover, this mismatch approach (i.e., using a cross-reactive hapten tracer) has never been reported in the literature. When compared with equilibrium dialysis combined with ultra-performance liquid chromatography/tandem mass spectrometry (ED-UPLC/MS/MS), this novel MST method yields similar binding affinity values for polyclonal antibodies to the major heroin metabolites 6-AM and morphine...
April 19, 2018: Analytical and Bioanalytical Chemistry
Nicolas Chuard, Amalia I Poblador-Bahamonde, Lili Zong, Eline Bartolami, Jana Hildebrandt, Wolfgang Weigand, Naomi Sakai, Stefan Matile
The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines...
February 21, 2018: Chemical Science
Saskia Roesch, Thomas Lindner, Max Sauter, Anastasia Loktev, Paul Flechsig, Martin Müller, Walter Mier, Rolf Warta, Gerhard Dyckhoff, Christel Herold-Mende, Uwe Haberkorn, Annette Altmann
Alpha v beta 6 (αvβ6) integrin is overexpressed by several carcinomas, and thus considered as target for diagnostic imaging and anti-cancer therapies. Recently, we presented SFITGv6 as a novel potential tracer for imaging and targeted therapy of αvβ6 integin-positive carcinomas. Here, we analyzed affinity and specificity of five native αvβ6 integrin-specific binders in comparison to SFITGv6. Methods: Sunflower trypsin inhibitor (SFTI)-1-based peptides containing arginine-glycine-aspartic acid (RGD) motif-spanning octamers of fibronectin (SFFN1), tenascin C (SFTNC), vitronectin (SFVTN), and latency-associated peptides (LAP) 1 (SFLAP1), and 3 (SFLAP3) were synthesized and their binding potential to αvβ6 integrin-expressing head and neck squamous cell carcinoma (HNSCC) cell lines was evaluated...
April 19, 2018: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Alexander J Winton, Janae L Baptiste, Mark A Allen
Proteins and polypeptides represent nature's most complex and versatile polymer. They provide complicated shapes, diverse chemical functionalities, and tightly regulated and controlled sizes. Several disease states are related to the misfolding or overproduction of polypeptides and yet polypeptides are present in several therapeutic molecules. In addition to biological roles; short chain polypeptides have been shown to interact with and drive the bio-inspired synthesis or modification of inorganic materials...
April 16, 2018: Protein Expression and Purification
Dengyue Sun, Dengke Gao, Panpan Xu, Qianqian Guo, Zhangliang Zhu, Xiaotao Cheng, Song Bai, Hui-Min Qin, Fuping Lu
Hydroxy amino acids are produced by Fe(II)/αKG-dependent dioxygenases and used widely as medicinal intermediates for chemical synthesis. A novel l-leucine 5-hydroxylase gene from Nostoc piscinale (NpLDO) was cloned into pET28a (+), pColdI and pQE-80 L plasmids. Using a two-step purification process (Ni-affinity chromatography and gel filtration), highly purified recombinant NpLDO was obtained. Recombinant NpLDO displayed unexpectedly high sulfoxidation activity toward l-methionine. The reaction products were analyzed by high-performance liquid chromatography...
April 16, 2018: Protein Expression and Purification
Soundappan S Mohanraj, Sarada D Tetali, Nalini Mallikarjuna, Aparna Dutta-Gupta, Kollipara Padmasree
Crude proteinase inhibitors (CPIs) extracted from the seeds of Rhynchosia sublobata, a wild relative of pigeon pea showed pronounced inhibitory activity on the larval gut trypsin-like proteases of lepidopteran insect pest - Achaea janata. Consequently, a full-length cDNA of Bowman-Birk inhibitor gene (RsBBI1) was cloned from the immature seeds of R. sublobata. It contained an ORF of 360 bp encoding a 119-amino acid polypeptide (13.3 kDa) chain with an N-terminus signal sequence comprising of 22 amino acids...
April 16, 2018: Phytochemistry
Pedro Henrique Reis da Silva, Melina Luiza Vieira Diniz, Gerson Antônio Pianetti, Isabela da Costa César, Maria Elisa Scarpelli Ribeiro E Silva, Roberto Fernando de Souza Freitas, Ricardo Geraldo de Sousa, Christian Fernandes
Lumefantrine is the first-choice treatment of Falciparum uncomplicated malaria. Recent findings of resistance to lumefantrine has brought attention for the importance of therapeutic monitoring, since exposure to subtherapeutic doses of antimalarials after administration is a major cause of selection of resistant parasites. Therefore, this study focused on the development of innovative, selective, less expensive and stable molecularly imprinted polymers (MIPs) for solid-phase extraction (SPE) of lumefantrine from human plasma to be used in drug monitoring...
July 1, 2018: Talanta
Maryam S Abunnaja, Fatemah A Alherz, Amal A El Daibani, Ahsan F Bairam, Mohammed Ibrahim Rasool, Saud A Gohal, Katsuhisa Kurogi, Yoichi Sakakibara, Masahito Suiko, Ming-Cheh Liu
The cytosolic sulfotransferase (SULT) SULT2A1 is known to mediate the sulfation of dehydroepiandrosterone (DHEA) as well as some other hydroxysteroids such as pregnenolone. The present study was designed to investigate how genetic polymorphisms of the human SULT2A1 gene may affect the sulfation of DHEA and pregnenolone. Online databases were systematically searched to identify human SULT2A1 single nucleotide polymorphisms (SNPs). Of the 98 SULT2A1 non-synonymous coding SNPs identified, seven were selected for further investigation...
April 19, 2018: Biochemistry and Cell Biology, Biochimie et Biologie Cellulaire
Joanna Krajewska, Zbigniew Arent, Michal Zolkiewski, Sabina Kędzierska-Mieszkowska
Bacterial ClpB is an ATP-dependent Hsp100 chaperone that reactivates aggregated proteins in cooperation with the DnaK chaperone system and promotes survival of bacteria under stress conditions. A large number of publications also indicate that ClpB supports the virulence of bacteria, including a pathogenic spirochaete Leptospira interrogans responsible for leptospirosis in both animals and humans. However, the exact role of ClpB in bacterial pathogenicity remains poorly characterized. It can be assumed that ClpB, due to its role as the molecular chaperone, mediates refolding of essential bacterial proteins, including the known virulence factors, which may become prone to aggregation under infection-induced stresses...
April 18, 2018: International Journal of Molecular Sciences
Jiyae Jung, Youngmi Kim, Jinhoi Song, Yae Jin Yoon, Da-Eun Kim, Joo Ae Kim, Yena Jin, Yu-Jin Lee, Seokho Kim, Byoung-Mog Kwon, Dong Cho Han
We hypothesized that Octamer-binding transcription factor 4 (OCT4) inhibition would have therapeutic benefits in Testicular germ cell tumors (TGCT). To identify inhibitors of OCT4, a chemical library was screened using a luciferase reporter system under the control of an OCT4 response element. A compound named KRIBB53 was identified based on its blocking of OCT4-dependent luciferase activation. When NCCIT cells were exposed to KRIBB53, the expression levels of OCT4 target genes, such as NANOG and USP44, were inhibited with an IC50 of 13 and 15 μM, respectively...
April 13, 2018: Carcinogenesis
Juan-Juan Chen, Si-Yong Huang, Peng-Fei Ma, Bi-Jia Wu, Si-Lang Zhou, Yong-Xing Zhao, Jun-Mei Gong, Ying-Min Liang
OBJECTIVE: To express and purify the mouse endothelial cell-targeted recombinant Notch ligand protein mD1R, and to investigate its effect on hematopoiesis after carbon tetrachloride damage. METHODS: PCR was performed to clone and construct the expression vector pET22b(+)-mD1R. The mD1R successfully transformed into E. coli was induced by IPTG, and purified with Ni2+ -beads affinity chromatography. The target protein was detected by SDS-PAGE. The fluorescence-activated cell sorting analysis (FACS), cell adhesion test, immunofluorescence staining and quantitative real-time PCR were employed to detect the endothelial cell-targeted and Notch signaling-activated biological characteristics of mD1R...
April 2018: Zhongguo Shi Yan Xue Ye Xue za Zhi
Yong Cui, Yao Wang, Xuelin Wang, Zhengwei Zhang, Jinghai Zhang, Yongshan Zhao
Scorpion venom is composed of a large number of bioactive peptides which display important pharmacological activities. In this study we have carried out a study of the functional role of the arginine residue at position 58 in the site RC comprising the reverse turn (8-12) and C-terminal residues 58-64. A polymerase chain reaction was used to substitute this arginine residue with a single amino acid such as alanine, glycine and lysine. The mutants were expressed in soluble form in E. coli, and purified by affinity chromatography...
April 9, 2018: Computational Biology and Chemistry
Emmanuel Bourgogne, Benoit Culot, Sylvie Dell'Aiera, Hugues Chanteux, Armel Stockis, Jean-Marie Nicolas
Brivaracetam (BRV) is a new high affinity synaptic vesicle protein 2A ligand recently approved for adults with partial-onset seizures. As a support to in vitro metabolism assays, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method coupled to off-line solid phase extraction (SPE) was developed to quantify BRV acid metabolites, that is, BRV-AC (carboxylic derivative derived from BRV hydrolysis) and BRV-OHAC (corresponding to hydroxylated BRV-AC). The method was validated for various incubates (liver and kidney tissue homogenates and blood, all from humans) and applied to in vitro metabolism assays...
April 10, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Karla Tonelli Bicalho Crosara, David Zuanazzi, Eduardo Buozi Moffa, Yizhi Xiao, Maria Aparecida de Andrade Moreira Machado, Walter Luiz Siqueira
Understanding proteins present in saliva and their function when isolated is not enough to describe their real role in the mouth. Due to protein-protein interactions, structural changes may occur in macromolecules leading to functional modulation or modification. Besides amylase's function in carbohydrate breakdown, amylase can delay proteolytic degradation of protein partners (e.g., histatin 1) when complexed. Due to its biochemical characteristics and high abundance in saliva, amylase probably interacts with several proteins acting as a biological carrier...
2018: BioMed Research International
Qinying Li, Guoyun Li, Xiaoliang Zhao, Xindi Shan, Chao Cai, Jing Zhao, Fuming Zhang, Robert J Linhardt, Guangli Yu
As an important glycosaminoglycan, keratan sulfate (KS) mainly exists in corneal and cartilage, possessing various biological activities. In this study, we purified KS from blue shark ( Prionace glauca ) cartilage and prepared KS oligosaccharides (KSO) through keratanase II-catalyzed hydrolysis. The structures of KS and KSO were characterized using multi-dimensional nuclear magnetic resonance (NMR) spectra and liquid chromatography-mass spectrometry (LC-MS). Shark cartilage KS was highly sulfated and modified with ~2...
April 14, 2018: Marine Drugs
Peng Huang, Qingwen Sun, Weijun Shi, Wangchun Du, Xue Li, Ning Zhang
Infectious diseases caused by antibiotic multidrug-resistant microorganisms are major causes of morbidity and mortality in humans. Hence, there is an urgent need to search for new antimicrobial agents. Initially known as a defensive effector in the innate immunity of certain organs of the human body, human goose-type lysozyme 2 (hLysG2) has been shown to possess therapeutically useful potential against multidrug-resistant microorganisms. Developing a novel strategy for large-scale production that provides high yields of this protein with high purity, quality, and potency is critical for pharmaceutical applications...
April 13, 2018: Journal of Biotechnology
Ying Lou, Guorong Ji, Qin Liu, Pengbo Wang, Ruilin Zhang, Yuanxing Zhang, Xiaohong Liu
The human thyroid peroxidase (hTPO) is an essential enzyme for thyroid hormone biosynthesis and is expressed in thyroid cells. It is an autoantigen against which antibodies are found in the sera of patients with a number of autoimmune thyroid disorders. Overexpression of hTPO has been achieved using the baculovirus expression vector system (BEVS). However, it is produced largely in an aggregated form in the cell lysate fraction, which increases the complexity of protein extraction. In this study, to achieve improved secretory expression of hTPO via BEVS, a truncated recombinant hTPO protein (hTPOt) was engineered by replacing its original signal peptide (SP) in the N-terminal with five heterologous SPs...
April 12, 2018: Protein Expression and Purification
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"