ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPulmonary surfactant-associated protein A enhances the surface activity of lipid extract surfactant and reverses inhibition by blood proteins in vitroAmanda M. Cockshutt, Jeffrey Weitz, Fred PossmayerCite this: Biochemistry 1990, 29, 36, 8424–8429Publication Date (Print):September 11, 1990Publication History Published online1 May 2002Published inissue 11 September...

ABSTRACT Traditional microscope-based estimates of species richness aquatic hyphomycetes depend upon the ability in community to sporulate. Molecular techniques which detect DNA from all stages life cycle could potentially circumvent problems associated with traditional methods. Leaf disks red maple, alder, linden, beech, and oak as well birch wood sticks were submerged a stream southeastern Canada for 7, 14, 28 days. Fungal biomass, estimated by amount ergosterol present, increased time on...

Abstract Diatoms host chlorophyll a/c chloroplasts distinct from green chloroplasts. now dominate the eukaryotic oceanic phytoplankton, in part through their exploitation of environments with variable light. We grew marine diatoms across a range temperatures and then analyzed PSII function subunit turnover during an increase light to mimic upward mixing event. The small diatom Thalassiosira pseudonana initially responds increased photoinactivation under blue or white rapid acceleration...

Iron is an essential component in many protein complexes involved photosynthesis, but environmental iron availability often low as oxidized forms of are insoluble water. To adjust to levels, cyanobacteria undergo numerous changes balance their budget and mitigate the physiological effects depletion. We investigated key abundances photophysiological parameters model Synechococcus PCC 7942 Synechocystis 6803 over a 120 hour time course deprivation. The stress induced (IsiA) accumulated high...

The effect of surfactant concentration and supplementation with surfactant-associated protein A (SP-A) on the surface activity lipid extract (LES) was examined using a captive bubble technique. Adsorption LES is strongly dependent over range 50-1,000 micrograms/ml. Addition SP-A to at low concentrations in presence calcium dramatically increases rate adsorption. In quasistatic cycling experiments, samples containing require less compression achieve tensions even during first cycle....

We quantified and compared the photophysiological characteristics of Emiliania huxleyi with two marine diatoms Thalassiosira pseudonana Coscinodiscus sp. under nitrogen‐ phosphorus‐replete ‐depleted conditions. Under nitrogen‐depleted conditions, E. maintained significant photosystem II (PSII) function over at least 38 d, whereas for both diatoms, PSII declined to marginal levels within 8‐10 d nitrogen depletion. In contrast, phosphorus‐depleted in sharply 7 T. 3 d. nutrient‐replete had one...

Iron availability limits primary production in >30% of the world’s oceans; hence phytoplankton have developed acclimation strategies. In particular, cyanobacteria express IsiA (iron‐stress‐induced) under iron stress, which can become most abundant chl‐binding protein cell. Within iron‐limited oceanic regions with significant cyanobacterial biomass, may represent a fraction total chl. We spectroscopically measured effective cross‐section photosynthetic reaction center PSI (σ ) vivo and...

Micromonas strains of small prasinophyte green algae are found throughout the world's oceans, exploiting widely different niches. We grew arctic and temperate compared their susceptibilities to photoinactivation Photosystem II, counteracting II repair capacities, content, induction relaxation non-photochemical quenching. In strain NCMA 2099, cellular content active represents only about 50 % total protein, as a slow rate constant for clearance PsbA protein limits instantaneous repair....

Assessing the effect of light pollution, Microcystis aeruginosa was grown with and without low levels night lighting. Significant differences were observed between treatments in maximum quantum yield charge separation, intracellular chlorophyll a concentration, functional absorption cross-section photosystem II, number Rubisco per cell a, I fraction not bound to photosystems IsiA.

Marine Synechococcus and Prochlorococcus are picocyanobacteria predominating in subtropical, oligotrophic marine environments, a niche predicted to expand with climate change. When grown under common low light conditions WH 8102 MED 4 show similar Cytochrome b6f Photosystem I contents normalized II content, while MIT 9313 has twice the content four times of other strains. Interestingly, strains contain only one third half RUBISCO catalytic subunits compared strain. The maximum electron...

Marine diatoms are photosynthetic, and thrive in environments where light fluctuates. Like all oxygenic photosynthetic organisms face a light-dependent inactivation of the Photosystem II complexes that photooxidize water to generate biosynthetic reductant. To maintain photosynthesis this photoinactivation must be countered by slow metabolically expensive protein turnover, which is dependent cyanobacteria plants. We tracked daily cycles content, synthesis degradation II, small large marine...

Physiological and environmental stressors can cause osmotic stress in fish hearts, leading to a reduction intracellular taurine concentration. Taurine is β-amino acid known regulate cardiac function other animal models but its role has not been well characterized. We generated model of deficiency (TD) by feeding brook char (Salvelinus fontinalis) diet enriched β-alanine, which inhibits cardiomyocyte uptake. Cardiac levels were reduced 21% stress-induced changes normal handling observed TD...

Photoautotrophs share core pathways for primary productivity and elemental cycling. These paths are generally mediated by abundant protein complexes which conserved across wide taxonomic ranges, quantitatively dominate the proteomes of photoautotrophs. Quantification key pools is a powerful approach to measure resource allocations maximal catalytic capacities biological functions, comparing species or communities, tracking change over time within communities. Protein quantification can be...

The jawless fish, the sea lamprey (Petromyzon marinus), spends part of its life as a burrow‐dwelling, suspension‐feeding larva (ammocoete) before undergoing metamorphosis into free swimming, parasitic juvenile that feeds on blood fishes. We predicted animals in this juvenile, stage have great capacity for catabolizing amino acids when large quantities protein‐rich are ingested. sixfold to 20‐fold greater ammonia excretion rates (JAmm) postmetamorphic (nonfeeding) and lampreys compared with...

DNA content and cell volume have both been hypothesized as controls on metabolic rate other physiological traits. We use cultures of two cryptic species Ditylum brightwellii (West) Grunow with an approximately two-fold difference in genome size a small large culture each clone obtained by isolating cells to compare the consequences changes due differences reduction following many generations asexual reproduction. quantified growth rate, functional absorption cross-section photosystem II...

Polar microalgae face two major challenges: 1- growing at temperatures (-1.7 to 5°C) that limit enzyme kinetics; and 2- surviving exploiting a wide range of irradiance. The objective this study is understand the adaptation an Arctic diatom its environment by studying ability acclimate changes in light temperature. We acclimated polar Chaetoceros neogracilis various levels different studied growth photosynthetic properties using semi-continuous cultures. Rubisco content was high, compensate...