5% (w/v) sodium lauroyl sarcosinate as solubilizing agent and subsequent purification by affinity chromatography using a glutathione agarose column. The removal of the GST tag by Factor Xa enzymatic cleavage and purification by HPLC yielded as much as similar to 7 mg and similar to 1.5 Batimastat mg of unlabeled A beta(1-40) and uniformly N-15- and/or C-13-protein A beta(1-40) from 1 L of the cell culture, respectively. Mass spectroscopy of unlabeled and labeled A beta and H-1/N-15 HSQC solution NMR spectrum of the obtained N-15-labeled A beta in the monomeric form confirmed the expression of native A beta(1-40). It was also confirmed
by electron micrography and solid-state NMR analysis that the purified A beta(1-40) self-assembles into beta-sheet rich amyloid fibrils. To the best of our knowledge, our protocol offers the highest yields among published protocols for production of recombinant A beta(1-40) samples that are amendable for an NMR-based structural analysis. The protocol may be applied to efficient preparation of other amyloid-forming proteins and peptides that are C-13- and N-15-labeled for NMR experiments. (C) 2011
Elsevier Inc. All rights reserved.”
“Barnacles, which are sedentary XAV 939 marine crustaceans, have diverse sexual systems that include simultaneous hermaphroditism, androdioecy (coexistence of hermaphrodites and males) and dioecy (females and males). In dioecious and androdioecious species, the males are very small and are thus called dwarf males. These sexual systems are defined by two factors: sex allocation of non-dwarf individuals and the presence or absence of dwarf males. We constructed an ESS model treating sex allocation see more and life history simultaneously to explain sexual systems in barnacles. We analyzed the evolutionarily stable size-dependent resource allocation strategy to male reproductive function, female reproductive function and growth in non-dwarf barnacles, and the ESS proportion of dwarf males, under conditions
of varying mortality and food availability. Sex allocation in non-dwarf individuals (hermaphrodites or females) is affected by mate availability and the proportion of dwarf males. When hermaphrodites appear, all hermaphrodites become protandric simultaneous hermaphrodites. Furthermore, high mortality and poor resource availability favor dwarf males because of their early maturation and weakened sperm competition. In conclusion, we showed that combining sex allocation and life history theories is a useful way to understand various sexual systems in barnacles and perhaps in other organisms as well. (c) 2012 Elsevier Ltd. All rights reserved.”
“Membrane-bound pyrophosphatases (M-PPases) are enzymes that couple the hydrolysis of inorganic pyrophosphate to pumping of protons or sodium ions.