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Full-Text Articles in Biochemistry
Water Chemistry Dynamics In Four Vernal Pools In Maine, Usa, Lydia H. Kifner
Water Chemistry Dynamics In Four Vernal Pools In Maine, Usa, Lydia H. Kifner
Electronic Theses and Dissertations
Vernal pools are small seasonal wetlands that are a common landscape feature that contribute to biodiversity in northeastern North American forests. However, even basic information about their biogeochemical functions, such as carbon cycling, is limited. Dissolved gas concentrations (CH4, CO2) and other water chemistry parameters were monitored weekly at the bottom and surface of four vernal pools in central and eastern Maine, USA, from April to August 2016. The vernal pools were supersaturated with respect to CH4 and CO2 at all sampling dates and locations. Concentrations of dissolved CH4 and CO2 ranged …
Influence Of Histidine Residues, Ph And Charge Interactions On Membrane-Spanning Peptides, Ashley N. Henderson
Influence Of Histidine Residues, Ph And Charge Interactions On Membrane-Spanning Peptides, Ashley N. Henderson
Graduate Theses and Dissertations
Designed transmembrane peptides were employed for investigations of histidine residues within the hydrophobic environment of the lipid bilayer by means of oriented solid-state deuterium NMR spectroscopy. Using the model peptide GWALP23 sequence (GGALW(LA)6LWLAGA) as a host framework, the effects of single and double histidine mutations were explored. Replacement of leucine residue 12 to polar neutral histidine had little influence on the peptide average orientation, however under strongly acidic pH conditions in DOPC bilayers, the histidine becomes positively charged (pKa 2.5) and the GWALP23-H12 peptide exits the membrane and adopts a surface-bound orientation. Conversely, mutation of leucine 14 to neutral histidine …