The United States' next generation of atmospheric composition and coastal ecosystem measurements : NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission

Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 93 (2012): 1547–1566, doi:10.1175/BAMS-D-11-00201.1.The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission was recommended by the National Research Council's (NRC's) Earth Science Decadal Survey to measure tropospheric trace gases and aerosols and coastal ocean phytoplankton, water quality, and biogeochemistry from geostationary orbit, providing continuous observations within the field of view. To fulfill the mandate and address the challenge put forth by the NRC, two GEO-CAPE Science Working Groups (SWGs), representing the atmospheric composition and ocean color disciplines, have developed realistic science objectives using input drawn from several community workshops. The GEO-CAPE mission will take advantage of this revolutionary advance in temporal frequency for both of these disciplines. Multiple observations per day are required to explore the physical, chemical, and dynamical processes that determine tropospheric composition and air quality over spatial scales ranging from urban to continental, and over temporal scales ranging from diurnal to seasonal. Likewise, high-frequency satellite observations are critical to studying and quantifying biological, chemical, and physical processes within the coastal ocean. These observations are to be achieved from a vantage point near 95°–100°W, providing a complete view of North America as well as the adjacent oceans. The SWGs have also endorsed the concept of phased implementation using commercial satellites to reduce mission risk and cost. GEO-CAPE will join the global constellation of geostationary atmospheric chemistry and coastal ocean color sensors planned to be in orbit in the 2020 time frame.Funding for GEO-CAPE definition activities is provided by the Earth Science Division of the National Aeronautics and Space Administration.2013-04-0

Recombinant Soluble Respiratory Syncytial Virus F Protein That Lacks Heptad Repeat B, Contains a GCN4 Trimerization Motif and Is Not Cleaved Displays Prefusion-Like Characteristics

The respiratory syncytial virus (RSV) fusion protein F is considered an attractive vaccine candidate especially in its prefusion conformation. We studied whether recombinant soluble RSV F proteins could be stabilized in a prefusion-like conformation by mutation of heptad repeat B (HRB). The results show that soluble, trimeric, non-cleaved RSV F protein, produced by expression of the furin cleavage site-mutated F ectodomain extended with a GCN4 trimerization sequence, is efficiently recognized by pre- as well as postfusion-specific antibodies. In contrast, a similar F protein completely lacking HRB displayed high reactivity with prefusion-specific antibodies recognizing antigenic site Ø, but did not expose postfusion-specific antigenic site I, in agreement with this protein maintaining a prefusion-like conformation. These features were dependent on the presence of the GCN4 trimerization domain. Absence of cleavage also contributed to binding of prefusion-specific antibodies. Similar antibody reactivity profiles were observed when the prefusion form of F was stabilized by the introduction of cysteine pairs in HRB. To study whether the inability to form the 6HB was responsible for the prefusion-like antibody reactivity profile, alanine mutations were introduced in HRB. Although introduction of alanine residues in HRB inhibited the formation of the 6HB, the exposure of postfusion-specific antigenic site I was not prevented. In conclusion, proteins that are not able to form the 6HB, due to mutation of HRB, may still display postfusion-specific antigenic site I. Replacement of HRB by the GCN4 trimerization domain in a non-cleaved soluble F protein resulted, however, in a protein with prefusion-like characteristics, suggesting that this HRB-lacking protein may represent a potential prefusion F protein subunit vaccine candidate