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VV. R. PHILIPSON F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1987,95(1):19-25
Problems presented by genera, or small groups of genera, which have been given family rank are reviewed, and the genera are divided into a number of categories according to the closeness of their affinity to other genera or families. Satellite genera that stand in close relation to families should be united with them. Binary families, that have been divided into two (or more) related families, should be re–united. Families connected by linking genera, should, logically, be united but practical considerations usually prevent this. Clusters of diverse but more or less distantly related genera present unusual problems, being treated either as several, often monogeneric families or as a loosely structured family. Truly isolated genera must be given family and often ordinal rank. 相似文献
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Florian Kleefeldt Heike Bmmel Britta Broede Michael Thomsen Verena Pfeiffer Philipp Wrsdrfer Srikanth Karnati Nicole Wagner Uwe Rueckschloss Süleyman Ergün 《Aging cell》2019,18(6)
Aging is an independent risk factor for cardiovascular diseases and therefore of particular interest for the prevention of cardiovascular events. However, the mechanisms underlying vascular aging are not well understood. Since carcinoembryonic antigen‐related cell adhesion molecule 1 (CEACAM1) is crucially involved in vascular homeostasis, we sought to identify the role of CEACAM1 in vascular aging. Using human internal thoracic artery and murine aorta, we show that CEACAM1 is upregulated in the course of vascular aging. Further analyses demonstrated that TNF‐α is CEACAM1‐dependently upregulated in the aging vasculature. Vice versa, TNF‐α induces CEACAM1 expression. This results in a feed‐forward loop in the aging vasculature that maintains a chronic pro‐inflammatory milieu. Furthermore, we demonstrate that age‐associated vascular alterations, that is, increased oxidative stress and vascular fibrosis, due to increased medial collagen deposition crucially depend on the presence of CEACAM1. Additionally, age‐dependent upregulation of vascular CEACAM1 expression contributes to endothelial barrier impairment, putatively via increased VEGF/VEGFR‐2 signaling. Consequently, aging‐related upregulation of vascular CEACAM1 expression results in endothelial dysfunction that may promote atherosclerotic plaque formation in the presence of additional risk factors. Our data suggest that CEACAM1 might represent an attractive target in order to delay physiological aging and therefore the transition to vascular disorders such as atherosclerosis. 相似文献
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Karnati VV Gao X Gao S Yang W Ni W Sankar S Wang B 《Bioorganic & medicinal chemistry letters》2002,12(23):3373-3377
A glucose selective diphenylboronic acid fluorescent sensor (10a) with a K(a) of 1472M(-1) has been synthesized and evaluated. This sensor shows a 43- and 49-fold selectivity for glucose over fructose and galactose, respectively. The binding affinity improvement is about 300-fold and the selectivity improvement for glucose over fructose is about 1400-fold compared with the monoboronic acid compound, phenylboronic acid. 1H NMR studies indicate that sensor 10a binds with alpha-D-glucofuranose in a bidentate manner (1:1 ratio). 相似文献
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Yang W Gao S Gao X Karnati VV Ni W Wang B Hooks WB Carson J Weston B 《Bioorganic & medicinal chemistry letters》2002,12(16):2175-2177
A series of fluorescent diboronic acids was synthesized in nine steps as potential sensors for sialyl Lewis X (sLex). The fluorescent binding studies of these sensors with sLex were carried out in a mixed aqueous solution. Compound 7e was found to show the strongest fluorescence enhancement upon binding with sLex. Using cell cultures, 7e was shown to label sLex-expressing HEPG2 cells at 1 microM, while non-sLex-expressing cells were not labeled. 相似文献
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Nageswara Rao P Yadaiah M Roy KR Potu H Bhuyan AK 《Protein expression and purification》2007,56(2):220-228
The apoptotic protease activating factor (Apaf-1) is central to the regulatory mechanism by which procaspase-9 is activated in the cytochrome c-mediated pathway of apoptosis. For a detailed biochemical and structural investigation of Apaf-1 function, we have cloned and expressed in Escherichia coli inclusion bodies the WD40-deleted protein (DeltaWD40 Apaf-1) from HepG2 cell. The construct contains an N-terminal His6 tag derived from the cloning vector so that the mass of the protein and the tag together is 51,594 Da, as determined by TOF/TOF mass spectrometric analysis. An optimized refolding protocol has allowed protein recovery in highly pure form. Basic fluorescence and CD probes indicate that the refolded protein retains secondary and tertiary structures, and unfolds in the presence of higher concentration of denaturant. The equilibrium ATP binding property of the protein has been measured by changes in fluorescence emission due to the fluorescent ATP analog, mant-ATP (2'(3')-O-(N-methylanthraniloyl) adenosine 5'-triphosphate). The results demonstrate a tight Apaf-1-ATP interaction, the binding affinity being 380 nM. 相似文献
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Phillip Grant Barbara Ahlemeyer Srikanth Karnati Timm Berg Ingra Stelzig Anca Nenicu Klaus Kuchelmeister Denis I. Crane Eveline Baumgart-Vogt 《Histochemistry and cell biology》2013,140(4):423-442
Catalase and ABCD3 are frequently used as markers for the localization of peroxisomes in morphological experiments. Their abundance, however, is highly dependent on metabolic demands, reducing the validity of analyses of peroxisomal abundance and distribution based solely on these proteins. We therefore attempted to find a protein which can be used as an optimal marker for peroxisomes in a variety of species, tissues, cell types and also experimental designs, independently of peroxisomal metabolism. We found that the biogenesis protein peroxin 14 (PEX14) is present in comparable amounts in the membranes of every peroxisome and is optimally suited for immunoblotting, immunohistochemistry, immunofluorescence, and immunoelectron microscopy. Using antibodies against PEX14, we could visualize peroxisomes with almost undetectable catalase content in various mammalian tissue sections (submandibular and adrenal gland, kidney, testis, ovary, brain, and pancreas from mouse, cat, baboon, and human) and cell cultures (primary cells and cell lines). Peroxisome labeling with catalase often showed a similar tissue distribution to the mitochondrial enzyme mitochondrial superoxide dismutase (both responsible for the degradation of reactive oxygen species), whereas ABCD3 exhibited a distinct labeling only in cells involved in lipid metabolism. We increased the sensitivity of our methods by using QuantumDots?, which have higher emission yields compared to classic fluorochromes and are unsusceptible to photobleaching, thereby allowing more exact quantification without artificial mistakes due to heterogeneity of individual peroxisomes. We conclude that PEX14 is indeed the best marker for labeling of peroxisomes in a variety of tissues and cell types in a consistent fashion for comparative morphometry. 相似文献
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Sunil Kumar Tripathi Sanjeev Kumar Singh Poonam Singh Palanisamy Chellaperumal Karnati Konda Reddy Chandrabose Selvaraj 《Journal of molecular recognition : JMR》2012,25(10):504-512
Cyclin‐dependent kinases (CDKs) are core components of the cell cycle machinery that govern the transition between phases during cell cycle progression. Abnormalities in CDKs activity and regulation are common features of cancer, making CDK family members attractive targets for the development of anticancer drugs. Their inhibitors have entered in clinical trials to treat cancer. Very recently, Heathcote et al. (J. Med. Chem. 2010, 53:8508–8522) have found a ligand BS194 that has a high affinity with CDK2 (IC50 = 3 nm ) but shows low affinity with CDK1 (IC50 = 30 nm ). To understand the selectivity, we used homology modeling, molecular docking, molecular dynamics, and free‐energy calculation to analyze the interactions. A rational three‐dimensional model of the CDK1/BS194 complex is built. We found that Leu83 is a key residue that recognizes BS194 more effectively with CDK2 with good binding free energies rather than CDK1. Energetic analysis reveals that van der Waals interaction and non‐polar contributions to solvent are favorable in the formation of complexes and amine group of the ligand, which plays a crucial role for binding selectivity between CDK2 and CDK1. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Sinha S Roy S Reddy BS Pal K Sudhakar G Iyer S Dutta S Wang E Vohra PK Roy KR Reddanna P Mukhopadhyay D Banerjee R 《Molecular cancer research : MCR》2011,9(3):364-374
It is a challenge to develop a universal single drug that can treat breast cancer at single- or multiple-stage complications, yet remains nontoxic to normal cells. The challenge is even greater when breast cancer-specific, estrogen-based drugs are being developed that cannot act against multistaged breast cancer complications owing to the cells differential estrogen receptor (ER) expression status and their possession of drug-resistant and metastatic phenotypes. We report here the development of a first cationic lipid-conjugated estrogenic derivative (ESC8) that kills breast cancer cells independent of their ER expression status. This ESC8 molecule apparently is nontoxic to normal breast epithelial cells, as well as to other noncancer cells. ESC8 induces apoptosis through an intrinsic pathway in ER-negative MDA-MB-231 cells. In addition, ESC8 treatment induces autophagy in these cells by interfering with the mTOR activity. This is the first example of an estrogen structure-based molecule that coinduces apoptosis and autophagy in breast cancer cells. Further in vivo study confirms the role of this molecule in tumor regression. Together, our results open new perspective of breast cancer chemotherapy through a single agent, which could provide the therapeutic benefit across all stages of breast cancer. 相似文献
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Babu Sudhamalla Mahesh Kumar Karnati R. Roy R. Sunil Kumar Abani K. Bhuyan 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013