Hsc66 substrate specificity is directed toward a discrete region of the iron-sulfur cluster template protein IscU

Hsc66 and Hsc20 comprise a specialized chaperone system important for the assembly of iron-sulfur clusters in Escherchia coli. Only a single substrate, the Fe/S template protein IscU, has been identified for the Hsc66/Hsc20 system, but the mechanism by which Hsc66 selectively binds IscU is unknown. We have investigated Hsc66 substrate specificity using phage display and a peptide array of IscU. Screening of a heptameric peptide phage display library revealed that Hsc66 prefers peptides with a centrally located Pro-Pro motif. Using a cellulose-bound peptide array of IscU we determined that Hsc66 interacts specifically with a region (residues 99-103, LPPVK) that is invariant among all IscU family members. A synthetic peptide (ELPPVKIHC) corresponding to IscU residues 98-106 behaves in a similar manner to native IscU, stimulating the ATPase activity of Hsc66 with similar affinity as IscU, preventing Hsc66 suppression of bovine rhodanese aggregation, and interacting with the peptide-binding domain of Hsc66. Unlike native IscU, however, the synthetic peptide is not bound by Hsc20 and does not synergistically stimulate Hsc66 ATPase activity with Hsc20. Our results indicate that Hsc66 and Hsc20 recognize distinct regions of IscU and further suggest that Hsc66 will not bind LPPVK motifs with high affinity in vivo unless they are in the context of native IscU and can be directed to Hsc66 by Hsc20

Object oriented programming interfaces for accelerator control

Several years ago, the AGS controls group was given the task of developing software for the RHIC accelerator. Like the AGS, the RHIC control system needs to control and monitor equipment distributed around a relatively large geographic area. A local area network connects this equipment to a collection of UNIX workstations in a central control room. Similar software had been developed for the AGS about a decade earlier, but isn`t well suited for RHIC use for a number of reasons. Rather than adapt the AGS software for RHIC use, the controls group opted to start with a clean slate. To develop software that would address the shortcomings of the AGS software, while preserving the useful features that evolved through years of use. A current trend in control system design is to provide an object oriented programming interface for application developers. This talk will discuss important aspects and features of object oriented application programming interfaces (APIs) for accelerator control systems, and explore why such interfaces are becoming the norm

Increased leukotriene C 4 and vasogenic edema surrounding brain tumors in humans

Leukotrines are pharmacologically active compounds that promote vascular permeability. In this study we sought to determine whether tissue leukotriene–like immunoreactivity was increased in intracranial tumors associated with peritumoral edema. In 20 patients undergoing craniotomy tissue specimens were immediately frozen after removal and tissue leukotriene C 4 levels were determined by radioimmunoassay. An index of peritumoral edema was estimated from preoperative contrast-enhanced computed tomographic scans. There was a significant correlation between brain edema and tissue leukotriene levels ( p < 0.003). Metastatic tumors (n = 8) had the highest leukotriene C 4 level at 13.8 ± 8.5 pg/mg tissue (mean ± SE) and the highest index of edema 5.7 ± 1.8. The mean leukotriene C 4 level in the gliomas (n + 5) ws 6.2 ± 2.3 pg/mg tissue and the edema index was 2.1 ± 0.6. There was no edema and no neoplasma in he temporal lobes removed for seizure (n + 2), and their level of leukotriene C 4 was 0.4 ± 0.1 pg/mg tissue. The formation of leukotriene C 4 is stimulated by intracranial tumors. Leukotrienes increase blood–brain barrier permeability and may be important in the formation of vasogenic edema surrounding tumors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50315/1/410190613_ftp.pd

Diffusion MRI in early cancer therapeutic response assessment

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136261/1/nbm3458_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136261/2/nbm3458.pd