Tissue Specificity of Human Angiotensin I-Converting Enzyme.

BACKGROUND: Angiotensin-converting enzyme (ACE), which metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling, as well as in reproductive functions, is expressed as a type-1 membrane glycoprotein on the surface of endothelial and epithelial cells. ACE also presents as a soluble form in biological fluids, among which seminal fluid being the richest in ACE content - 50-fold more than that in blood. METHODS/PRINCIPAL FINDINGS: We performed conformational fingerprinting of lung and seminal fluid ACEs using a set of monoclonal antibodies (mAbs) to 17 epitopes of human ACE and determined the effects of potential ACE-binding partners on mAbs binding to these two different ACEs. Patterns of mAbs binding to ACEs from lung and from seminal fluid dramatically differed, which reflects difference in the local conformations of these ACEs, likely due to different patterns of ACE glycosylation in the lung endothelial cells and epithelial cells of epididymis/prostate (source of seminal fluid ACE), confirmed by mass-spectrometry of ACEs tryptic digests. CONCLUSIONS: Dramatic differences in the local conformations of seminal fluid and lung ACEs, as well as the effects of ACE-binding partners on mAbs binding to these ACEs, suggest different regulation of ACE functions and shedding from epithelial cells in epididymis and prostate and endothelial cells of lung capillaries. The differences in local conformation of ACE could be the base for the generation of mAbs distingushing tissue-specific ACEs

Ionospheric Response to Natural and Man Made Impacts

International audienceThe problem of energy transfer from the Earth’s solid mantles to the atmosphere and surrounding space is of essential importance for the fundamental geophysics and applied studies. These processes can largely govern the structure and dynamics of the phenomena developing in the near Earth space. Moreover, the consequences of such impacts as earthquakes, hurricanes, etc. upon the Earth’s electromagnetic field and ionosphere can become an extra factor in monitoring the processes involved in the upcoming large-scale seismic and meteorological catastrophes. The acoustic-gravity waves (comprising acoustic and gravity waves and hereafter referred to as AGW) are one of the most efficient ways to transport over the ionosphere the energy of the dynamic processes developing in the low atmosphere. The early experiments of the 1950’s and 60’s on Doppler sounding even showed that the ionosphere can serve as a sensitive indicator of natural and man made disturbances. The Doppler sounding of the ionosphere revealed impulse and wave disturbances excited by powerful sources of infrasound, such as: a) megaton nuclear explosions in the atmosphere, kiloton ground industrial explosions, b) earthquakes and volcano eruptions, c) thunderstorms, tornadoes and tsunamis, d) bolides and meteorites, e) rocket launches and flights of supersonicjets, f) aurora and solar eclipse