Goswami R.K.,0550 North Torrey Pines Road |
Bajjuri K.M.,0550 North Torrey Pines Road |
Forsyth J.S.,Scripps Research Institute |
Das S.,0550 North Torrey Pines Road |
And 7 more authors.
Bioconjugate Chemistry | Year: 2011
Integrins αvβ3 and αvβ6 are highly expressed on tumor cells and/or by the tumor vasculature of many human cancers, and represent promising targets for anticancer therapy. Novel chemically programmed antibodies (cpAbs) targeting these integrins were prepared using the catalytic aldolase Antibody (Ab) programming strategy. The effects of the cpAbs on cellular functions related to tumor progression were examined in vitro using tumor cell lines and their cognate integrin ligands, fibronectin and osteopontin. The inhibitory functions of the conjugates and their specificity were examined based on interference with cell-cell and cell-ligand interactions related to tumor progression. Cell binding analyses of the anti-integrin cpAbs revealed high affinity for tumor cells that overexpressed αvβ3 and αvβ6 integrins, and weak interactions with αvβ1 and αvβ8 integrins, in vitro. Functional analyses demonstrated that the cpAbs strongly inhibited cell-cell interactions through osteopontin binding, and they had little or no immediate effects on cell viability and proliferation. On the basis of these characteristics, the cpAbs are likely to have a broad range of activities in vivo, as they can target and antagonize one or multiple αv integrins expressed on tumors and tumor vasculatures. Presumably, these conjugates may inhibit the establishment of metastastatic tumors in distant organs through interfering with cell adhesion more effectively than antibodies or compounds targeting one integrin only. These anti-integrin cpAbs may also provide useful reagents to study combined effect of multiple αv integrins on cellular functions in vitro, on pathologies, including tumor angiogenesis, fibrosis, and epithelial cancers, in vivo. © 2011 American Chemical Society.
Grimster N.P.,0550 North Torrey Pines Road |
Connelly S.,CSIC - Biological Research Center |
Baranczak A.,0550 North Torrey Pines Road |
Dong J.,0550 North Torrey Pines Road |
And 6 more authors.
Journal of the American Chemical Society | Year: 2013
Molecules that bind selectively to a given protein and then undergo a rapid chemoselective reaction to form a covalent conjugate have utility in drug development. Herein a library of 1,3,4-oxadiazoles substituted at the 2 position with an aryl sulfonyl fluoride and at the 5 position with a substituted aryl known to have high affinity for the inner thyroxine binding subsite of transthyretin (TTR) was conceived of by structure-based design principles and was chemically synthesized. When bound in the thyroxine binding site, most of the aryl sulfonyl fluorides react rapidly and chemoselectively with the pK a-perturbed K15 residue, kinetically stabilizing TTR and thus preventing amyloid fibril formation, known to cause polyneuropathy. Conjugation t50s range from 1 to 4 min, ∼1400 times faster than the hydrolysis reaction outside the thyroxine binding site. X-ray crystallography confirms the anticipated binding orientation and sheds light on the sulfonyl fluoride activation leading to the sulfonamide linkage to TTR. A few of the aryl sulfonyl fluorides efficiently form conjugates with TTR in plasma. Eleven of the TTR covalent kinetic stabilizers synthesized exhibit fluorescence upon conjugation and therefore could have imaging applications as a consequence of the environment sensitive fluorescence of the chromophore. © 2013 American Chemical Society.
Rauniyar N.,0550 North Torrey Pines Road |
Gupta V.,Scripps Research Institute |
Gupta V.,University of California at San Diego |
Balch W.E.,Scripps Research Institute |
Yates J.R.,0550 North Torrey Pines Road
Journal of Proteome Research | Year: 2014
The most prevalent cause of cystic fibrosis (CF) is the deletion of a phenylalanine residue at position 508 in CFTR (ΔF508-CFTR) protein. The mutated protein fails to fold properly, is retained in the endoplasmic reticulum via the action of molecular chaperones, and is tagged for degradation. In this study, the differences in protein expression levels in CF cell models were assessed using a systems biology approach aided by the sensitivity of MudPIT proteomics. Analysis of the differential proteome modulation without a priori hypotheses has the potential to identify markers that have not yet been documented. These may also serve as the basis for developing new diagnostic and treatment modalities for CF. Several novel differentially expressed proteins observed in our study are likely to play important roles in the pathogenesis of CF and may serve as a useful resource for the CF scientific community. © 2014 American Chemical Society.
PubMed | 0550 North Torrey Pines Road
Type: Journal Article | Journal: Journal of virology | Year: 2011
Influenza virus hemagglutinin (HA) is the viral envelope protein that mediates viral attachment to host cells and elicits membrane fusion. The HA receptor-binding specificity is a key determinant for the host range and transmissibility of influenza viruses. In human pandemics of the 20th century, the HA normally has acquired specificity for human-like receptors before widespread infection. Crystal structures of the H1 HA from the 2009 human pandemic (A/California/04/2009 [CA04]) in complex with human and avian receptor analogs reveal conserved recognition of the terminal sialic acid of the glycan ligands. However, favorable interactions beyond the sialic acid are found only for 2-6-linked glycans and are mediated by Asp190 and Asp225, which hydrogen bond with Gal-2 and GlcNAc-3. For 2-3-linked glycan receptors, no specific interactions beyond the terminal sialic acid are observed. Our structural and glycan microarray analyses, in the context of other high-resolution HA structures with 2-6- and 2-3-linked glycans, now elucidate the structural basis of receptor-binding specificity for H1 HAs in human and avian viruses and provide a structural explanation for the preference for 2-6 siaylated glycan receptors for the 2009 pandemic swine flu virus.