Krishanu Ray

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KLP64D and KLP68D are members of the kinesin-II family of proteins in Drosophila. Immunostaining for KLP68D and ribonucleic acid in situ hybridization for KLP64D demonstrated their preferential expression in cholinergic neurons. KLP68D was also found to accumulate in cholinergic neurons in axonal obstructions caused by the loss of kinesin light chain.(More)
Many large double-stranded DNA viruses employ high force-generating ATP-driven molecular motors to package to high density their genomes into empty procapsids. Bacteriophage T4 DNA translocation is driven by a two-component motor consisting of the procapsid portal docked with a packaging terminase-ATPase. Fluorescence resonance energy transfer and(More)
Fluorescence spectroscopy is widely used in biological research. Until recently, essentially all fluorescence experiments were performed using optical energy which has radiated to the far-field. By far-field we mean at least several wavelengths from the fluorophore, but propagating far-field radiation is usually detected at larger macroscopic distances from(More)
Linear DNAs of any sequence can be packaged into empty viral procapsids by the phage T4 terminase with high efficiency in vitro. Packaging substrates of 5 kbp and 50 kbp, terminated by energy transfer dye pairs, were constructed from plasmid and lambda phage DNAs. Nuclease and fluorescence correlation spectroscopy (FCS) assays showed that approximately 20%(More)
We use finite-difference time-domain calculations to show that aluminum nanoparticles are efficient substrates for metal-enhanced fluorescence (MEF) in the ultraviolet (UV) for the label-free detection of biomolecules. The radiated power enhancement of the fluorophores in proximity to aluminum nanoparticles is strongly dependent on the nanoparticle size,(More)
We described, for the first time, the metal-enhanced fluorescence from the CdTe nanocrystals spin coated on silver island films (SIFs). CdTe nanocrystals show approximately 5-fold increase in fluorescence intensity, 3-fold decrease in lifetimes, and reduction in blinking on SIF surfaces that can be observed by ensemble and single-molecule fluorescence(More)
Bacteriophage T4 terminase packages DNA in vitro into empty small or large proheads (esps or elps). In vivo maturation of esps yields the more stable and voluminous elps required to contain the 170 kb T4 genome. Functional proheads can be assembled containing portal-GFP fusion proteins. In the absence of terminase activity these accumulated in esps in vivo,(More)
Viral genome packaging into capsids is powered by high-force-generating motor proteins. In the presence of all packaging components, ATP-powered translocation in vitro expels all detectable tightly bound YOYO-1 dye from packaged short dsDNA substrates and removes all aminoacridine dye from packaged genomic DNA in vivo. In contrast, in the absence of(More)
The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1(More)
Conserved bacteriophage ATP-based DNA translocation motors consist of a multimeric packaging terminase docked onto a unique procapsid vertex containing a portal ring. DNA is translocated into the empty procapsid through the portal ring channel to high density. In vivo the T4 phage packaging motor deals with Y- or X-structures in the replicative concatemer(More)