Samitabh Chakraborti

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We have cloned, expressed, and characterized the full-length and various soluble fragments of the SARS-CoV (Tor2 isolate) S glycoprotein. Cells expressing S fused with receptor-expressing cells at neutral pH suggesting that the recombinant glycoprotein is functional, its membrane fusogenic activity does not require other viral proteins, and that low pH is(More)
The entry of the SARS coronavirus (SCV) into cells is initiated by binding of its spike envelope glycoprotein (S) to a receptor, ACE2. We and others identified the receptor-binding domain (RBD) by using S fragments of various lengths but all including the amino acid residue 318 and two other potential glycosylation sites. To further characterize the role of(More)
Polyclonal antibodies have a century-old history of being effective against some viruses; recently, monoclonal antibodies (mAbs) have also shown success. The humanized mAb Synagis (palivizumab), which is still the only mAb against a viral disease approved by the US FDA, has been widely used as a prophylactic measure against respiratory syncytial virus(More)
The severe acute respiratory syndrome coronavirus (SARS-CoV) caused a worldwide epidemic in late 2002/early 2003 and a second outbreak in the winter of 2003/2004 by an independent animal-to-human transmission. The GD03 strain, which was isolated from an index patient of the second outbreak, was reported to resist neutralization by the human monoclonal(More)
Viral envelope glycoproteins are oligomeric and the quaternary structure is critical for their membrane fusion activity. Typically the transmembrane glycoproteins of class I fusion proteins contain the oligomerization domains and the surface glycoproteins (SU) are monomeric. However, it has been previously demonstrated [J. Biol. Chem. 277 (2002) 19727] that(More)
In the Moloney murine leukemia virus (MoMuLV) envelope glycoprotein (Env) we identified a membrane-proximal cytoplasmic domain (residues 598-616) that facilitates the Env incorporation into virions and Env-mediated fusion [Rozenberg, Y., Conner, J., Aguilar-Carreno, H., Chakraborti, S., Dimiter, D.S., Anderson, W.F., 2008. Viral entry: membrane-proximal(More)
Removal of the R peptide (residues 617-632) from the Moloney murine leukemia virus (MoMuLV) envelope protein (Env) cytoplasmic tail potentiates fusion. We examined the role of the membrane-proximal cytoplasmic domain (598-616) of the MoMuLV Env in the Env-mediated membrane fusion and incorporation. The Env truncated at 616 exhibits maximum fusogenicity in(More)
Naturally occurring human antibodies containing only heavy chain are very rare. All antibodies specific for HIV identified until now contain both light and heavy chains. By screening an immune HIV phage library we have identified an antibody, m12, that expresses only a heavy chain. The Fd of this heavy chain behaves as a CD4i antibody and binds gp120(More)
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