The feasibility of rebuilding and testing a nuclear thermal rocket (NTR) for the Mars mission has been investigated. Calculations indicate that an NTR would substantially reduce the earth-orbit assembled mass compared to L02/LH2 systems. The mass savings were 36% and 65% for the cases of total aerobraking and of total propulsive braking respectively. Consequently, the cost savings for a single ...

Procollagen C-proteinase enhancer (PCOLCE) proteins are extracellular matrix proteins that enhance the activities of procollagen C-proteinases by binding to the C-propeptide of procollagen I. PCOLCE proteins are built of three structural modules, consisting of two CUB domains followed by a C-terminal netrin-like (NTR) domain. While the enhancement of proteinase activity can be ascribed solely t...

Regional cerebral blood flow (rCBF) was measured in normotensive rate (NTR) and spontaneously hypertensive rats (SHR), in a lightly anesthetized state and with control of PaCO2 by artificial ventilation. Without carotid artery ligation, NTR and SHR showed almost identical rCBF values and distribution, despite significantly elevated levels of blood pressure in SHR. Bilateral carotid artery ligat...

The p75 neurotrophin receptor (p75(NTR)) contains a conserved death domain module similar to that of the cytotoxic receptors Fas and TNFR-1. Here, we describe the selection of peptide ligands from a combinatorial library using a variation of the selectively-infective phage (SIP) method directed to the death domain of p75(NTR). The binding sites on the death domain of p75(NTR) were identified fo...

Ligand-mediated dimerization has emerged as a universal mechanism of growth factor receptor activation. Neurotrophins interact with dimers of the p75 neurotrophin receptor (p75(NTR)), but the mechanism of receptor activation has remained elusive. Here, we show that p75(NTR) forms disulphide-linked dimers independently of neurotrophin binding through the highly conserved Cys(257) in its transmem...

The genome of Pseudomonas putida KT2440 encodes five proteins of the phosphoenolpyruvate-carbohydrate phosphotransferase system. Two of these (FruA and FruB) form a dedicated system for fructose intake, while enzyme I(Ntr) (EI(Ntr); encoded by ptsP), NPr (ptsO), and EII(Ntr) (ptsN) act in concert to control the intracellular accumulation of polyhydroxyalkanoates, a typical product of carbon ove...

NTR (nitroreductase NfsB from Escherichia coli) is a flavoprotein with broad substrate specificity, reducing nitroaromatics and quinones using either NADPH or NADH. One of its substrates is the prodrug CB1954 (5-[aziridin-1-yl]-2,4-dinitrobenzamide), which is converted into a cytotoxic agent; so NTR/CB1954 has potential for use in cancer gene therapy. However, wild-type NTR has poor kinetics an...

UNLABELLED The p75 neurotrophin receptor (p75(NTR)) is a multifunctional receptor that participates in many critical processes in the nervous system, ranging from apoptosis to synaptic plasticity and morphological events. It is a member of the tumor necrosis factor receptor (TNFR) superfamily, whose members undergo trimeric oligomerization. Interestingly, p75(NTR) interacts with dimeric ligands...

Besides the canonical phosphoenolpyruvate-dependent phosphotransferase system (PTS) for carbohydrate transport, most Proteobacteria possess the so-called nitrogen PTS (PTS(Ntr)) that transfers a phosphate group from phosphoenolpyruvate (PEP) over enzyme I(Ntr) (EI(Ntr)) and NPr to enzyme IIA(Ntr) (EIIA(Ntr)). The PTS(Ntr) lacks membrane-bound components and functions exclusively in a regulatory...

Both Reelin and Nerve Growth Factor (NGF) exert crucial roles in retinal development. Retinogenesis is severely impaired in E-reeler mice, a model of Reelin deficiency showing specific Green Fluorescent Protein expression in Rod Bipolar Cells (RBCs). Since no data are available on Reelin and NGF cross-talk, NGF and trkA(NGFR)/ p75(NTR) expression was investigated in retinas from E-reeler versus...