Airborne pollen and spores of León (Spain)

A qualitative and quantitative analysis of airborne pollen and spores was carried out over 2 years (from September 1987 to August 1989) in the city of León. Slides were prepared daily using a volumetric pollen trap, which was placed on the Faculty of Veterinary Science building (University of León) 12m above ground-level. Fifty-one pollen types were observed; the most important of these were: Cupressaceae during the winter,Pinus andQuercus in spring, and Poaceae, Leguminosae and Chenopodiaceae in the summer. The results also showed the existence of a rich mould spore assemblage in the atmosphere. The group of Amerospores (Penicillium, Aspergillus andCladosporium) as well as Dictyospores (Alternaria) were the most abundant;Puccinia was common in the air in August. Fluctuations in the total pollen and spores m³ of air were compared with meteorological parameters (temperature, relative humidity and rainfall). From the daily sampling of the atmosphere of León, considering the maximum and minimum temperature and duration of rainfall, the start of the pollen grain season was observed generally to coincide with a rise in temperature in the absence of rain.     

The β2 subunit of human placenta hexosaminidase (Hex) A and B is a non-random association of the two polypeptides αa and βb

The subunit structures of placental Hex A and B have previously been assigned as _a and _b, respectively. The ₂ subunit is composed of two non-identical polypeptide chains, _a and _b. Purified Hex A and B were fractionated on a chromatofocusing column, and the fractions were reduced and then alkylated with iodo-I-¹⁴C-acetamide. The polypeptide chains were separated by polyacrylamide-gel isoelectric focusing. From the radioactivity measurements of the polypeptides a constant value for ₂ was obtained in all the chromatofocusing fractions, demonstrating a non-random structure of (₂) in each ₂ subunit.     

Molecular basis for erythrocyte Le(a+b+) and salivary ABH partial-secretor phenotypes: expression of a FUT2 secretor allele with an A→T mutation at nucleotide 385 correlates with reducedα(1,2) fucosyltransferase activity

TheSe ^wA385T mutation of the FUT2 gene was found to correlate with both the erthrocyte Le(a+b+) and/or salivary ABH partial-secretor phenotypes of Polynesians. Constructs with FUT1 and FUT2 wild type genes, and the FUT2Se ^wA385T,se ^G428A andse ^C571T mutated alleles, were cloned into pcDNAI, and expressed in COS-7 cells. COS-7 cells transfected with theSe ^wA385T allele had weak, but detectable, (1,2)fucosyltransferase activity, with an acceptor substrate pattern similar to the wild type FUT2 gene. Comparative kinetic studies from cell extracts with mutatedSe ^wA385T and wild type FUT2 alleles gave similarK _m values, but less enzyme activity was present in cells transfected withSe ^wA385T (V _max 230 pmol h^–1 mg^–1), as compared to those transfected with FUT2 (V _max 1030 pmol h^–1 mg^–1), suggesting that the mutated enzyme is more unstable. These results confirm that the molecular basis for the erythrocyte Le(a+b+) and the associated ABH salivary partial-secretor phenotype, is an amino acid change of Ile 129Phe in the secretor (1,2)fucosyltransferase.Abbreviations (1,3/1,4)fucosyltransferase GDP-L-fucose:-D-N-acetylglucosaminide 3/4--L-fucosyltransferase - (1,2)fucosyltransferase GDP-L-fucose: -D-galactoside-2--L-fucosyltransferase - bp base pairs - FUT1 H gene; FUT2,Se gene - FUT3 Lewis gene or Fuc-TIll gene - FUT4 Fuc-TIV gene - FUT5 Fuc-TV gene - FUT6 Fuc-TVI gene - MAb monoclonal antibody - PCR polymerase chain reaction - RFLP restriction fragment length polymorphism - se ^G428A FUT2 nonsecretor GA mutation at nucleotide 428 - se ^C571T FUT2 nonsecretor CT mutation at nucleotide 571 - Se ^wA385T FUT2 secretor weak AT mutation at nucleotide 385 - SSP sequence specific primer     

Structure and Properties of a Complex of α-Synuclein and a Single-Domain Camelid Antibody

The aggregation of the intrinsically disordered protein α-synuclein to form fibrillar amyloid structures is intimately associated with a variety of neurological disorders, most notably Parkinson's disease. The molecular mechanism of α-synuclein aggregation and toxicity is not yet understood in any detail, not least because of the paucity of structural probes through which to study the behavior of such a disordered system. Here, we describe an investigation involving a single-domain camelid antibody, NbSyn2, selected by phage display techniques to bind to α-synuclein, including the exploration of its effects on the in vitro aggregation of the protein under a variety of conditions. We show using isothermal calorimetric methods that NbSyn2 binds specifically to monomeric α-synuclein with nanomolar affinity and by means of NMR spectroscopy that it interacts with the four C-terminal residues of the protein. This latter finding is confirmed by the determination of a crystal structure of NbSyn2 bound to a peptide encompassing the nine C-terminal residues of α-synuclein. The NbSyn2:α-synuclein interaction is mediated mainly by side-chain interactions while water molecules cross-link the main-chain atoms of α-synuclein to atoms of NbSyn2, a feature we believe could be important in intrinsically disordered protein interactions more generally. The aggregation behavior of α-synuclein at physiological pH, including the morphology of the resulting fibrillar structures, is remarkably unaffected by the presence of NbSyn2 and indeed we show that NbSyn2 binds strongly to the aggregated as well as to the soluble forms of α-synuclein. These results give strong support to the conjecture that the C-terminal region of the protein is not directly involved in the mechanism of aggregation and suggest that binding of NbSyn2 could be a useful probe for the identification of α-synuclein aggregation in vitro and possibly in vivo.     

Are Bryophytes Shade Plants? Photosynthetic Light Responses and Proportions of Chlorophyll a,Chlorophyll b and Total Carotenoids

BACKGROUND AND AIMS: Data are presented from 39 species of mosses and 16 liverworts for ratios of chlorophylls and total carotenoids, and light saturation of photosynthetic electron flow or photosynthetic CO2 uptake, in relation to the postulate that bryophyte cells in general show shade-plant characteristics. METHODS: Pigment concentrations were measured by spectrophotometer in 80 % acetone extracts. Light-saturation curves were constructed by (modulated) chlorophyll florescence and for some species by infra-red gas analysis. KEY RESULTS: The pigment measurements were widely variable but broadly in line with the findings of previous authors. Median values (mosses/liverworts) were: total chlorophyll, 1.64/3.76 mg g(-1); chlorophyll a : b, 2.29/1.99; chlorophylls : carotenoids, 4.74/6.75). The PPFD values at 95 % saturation (estimated from fitted curves) also ranged widely, but were almost all <1000 micromol m(-2) s(-1); the median for mosses was 583 and for liverworts 214 micromol m(-2) s(-1). The two highest PPFD95% values were from Polytrichum species with lamella systems forming a ventilated photosynthetic tissue. Total chlorophyll, chlorophyll a : b and chlorophylls : carotenoids all correlated significantly with PPFD95%. CONCLUSIONS: Bryophytes include but are not inherently shade plants. Light-saturation levels for species of open sun-exposed habitats are lower than for vascular sun plants and are probably limited by CO2 diffusion into unistratose leaves; this limit can only be exceeded by bryophytes with ventilated photosynthetic tissues which provide increased area for CO2 uptake.     

Stories and photographs of William A. Arnold (1904–2001), a pioneer of photosynthesis and a wonderful friend

William A. Arnold discovered many phenomena in photosynthesis. In 1932, together with Robert Emerson, he provided the first experimental data that led to the concept of a large antenna and a few reaction centers (photosynthetic unit); in 1935, he obtained the minimum quantum requirement of 8–10 for the evolution of one O₂ molecule; in 1951, together with Bernard L. Strehler, he discovered delayed fluorescence (also known as delayed light emission) in photosynthetic systems; and in 1956, together with Helen Sherwood, he discovered thermoluminescence in plants. He is also known for providing a solid-state picture of photosynthesis. Much has been written about him and his research, including many articles in a special issue of Photosynthesis Research (Govindjee et al. (eds.) 1996); and a biography of Arnold, by Govindjee and Srivastava (William Archibald Arnold (1904–2001), 2014), in the Biographical Memoirs of the US National Academy of Sciences, (Washington, DC). Our article here offers a glimpse into the everyday life, through stories and photographs, of this remarkable scientist.     

Pollen content study of the lower atmosphere in León (Spain) by use of a tethered balloon

This study was undertaken in order to understand thebehaviour of airborne pollen grains, namely therelationship between their concentrations andconcomitant meteorological parameters, at differentaltitudes (ground level, 200, 400 and 600 m) of thelower atmosphere and its daily variations over onesite (the experimental farm of the University ofLeón). The experimental design involved a tetheredballoon (2.25 m³), an ADAS remote meteorologicalstation and an original radio controlled three headedpollen and spore sampler (called GABIS) using theRotorod design. Each head sampled a differentaltitude, while two control samples were taken atground level. Twenty-one takeoffs could be realized inthe 5 weeks period between end of May and end of June1997. Sampling was done early in the morning and sampling time at each altitudewas of 15 minutes. Results show that 45 differenttypes of pollen grains could be collected at this timeof the year and that significant variations could beobserved in the behaviour of the pollen cloud on a dayto day basis, probably because of differentmeteorological situations. Contrary to what isgenerally believed, pollen was in most cases moreabundant at higher altitude – on average by 30% ascompared to ground level – making evident anaerobiological layer of transport at about 500 m aboveground. This was especially the case for trees (Quercus and Castanea). The atmosphere MixingRatio was the most explicative factor at 200 m, whiletemperature dominated significance analysis at both400 and 600 m.     

Crystallization and identification of a binary complex of a elastase-I and a Carboxypeptidase Aγ from porcine pancreas

A binary complex of elastase I and Carboxypeptidase Aγ has been isolated and crystallized from activated extracts of porcine pancreas. The purification procedure included ammonium sulfate fractionation and autolysis treatment followed by crystallization. The two components in the complex have been separated by DEAE-Sephadex A-50 column chromatography to homogeneity and their identification was demonstrated by NH₂-terminal sequence analysis. An analysis of the reconstitution crystal from the mixtures of both components showed that the complex consisted of a 1:1 molar ratio with elastase I and Carboxypeptidase Aγ, forming a binary complex in crystalline state.     

Microbiology and physiology of Cachaça (Aguardente) fermentations

Cachaça (aguardente) is a rum-style spirit made from sugar cane juice by artisanal methods in Brazil. A study was made of the production, biochemistry and microbiology of the process in fifteen distilleries in Sul de Minas. Identification of 443 yeasts showed Saccharomyces cerevisiae to be the predominant yeast but Rhodotorula glutinis and Candida maltosa were predominant in three cases. Bacterial infection is a potential problem, particularly in older wooden vats, when the ratio of yeasts:bacteria can be 10:1 or less. A study of daily batch fermentations in one distillery over one season in which 739 yeasts were identified revealed that S. cerevisiae was the predominant yeast. Six other yeast species showed a daily succession: Kluyveromyces marxianus, Pichia heimii and Hanseniaspora uvarum were present only at the beginning, Pichia subpelliculosa and Debaryomyces hansenii were detected from mid to the end of fermentation, and Pichia methanolica appeared briefly after the cessation of fermentation. Despite a steady influx of yeasts from nature, the species population in the fermenter was stable for at least four months suggesting strong physiological and ecological pressure for its maintenance. Cell densities during the fermentation were: yeasts – 4 × 10⁸/ml; lactic acid bacteria – 4 × 10⁵/ml; and bacilli – 5 × 10⁴/ml. Some acetic acid bacteria and enterobacteriaceae appeared at the end. Sucrose was immediately hydrolysed to fructose and glucose. The main fermentation was complete after 12 hours but not all fructose was utilised when harvesting after 24 hours.     

Towards a more accurate future for chlorophyll a and b determinations: the inaccuracies of Daniel Arnon’s assay

Photosynthesis Research - A recent publication (Esteban in New Phytol 217:341–342, 2018) describes how the use and citation of the assay of chlorophylls a and b extracted in aqueous 80%...     

Characterization and expression pattern of zebrafish Anti-Müllerian hormone (Amh) relative to sox9a, sox9b, and cyp19a1a, during gonad development

The role of Anti-Müllerian hormone (Amh) during gonad development has been studied extensively in mammals, but is less well understood in other vertebrates. In male mammalian embryos, Sox9 activates expression of Amh, which initiates the regression of the Mullerian ducts and inhibits the expression of aromatase (Cyp19a1), the enzyme that converts androgens to estrogens. To better understand shared features of vertebrate gonadogenesis, we cloned amh cDNA from zebrafish, characterized its genomic structure, mapped it, analyzed conserved syntenies, studied its expression pattern in embryos, larvae, juveniles, and adults, and compared it to the expression patterns of sox9a, sox9b and cyp19a1a. We found that the onset of amh expression occurred while gonads were still undifferentiated and sox9a and cyp19a1a were already expressed. In differentiated gonads of juveniles, amh showed a sexually dimorphic expression pattern. In 31 days post-fertilization juveniles, testes expressed amh and sox9a, but not cyp19a1a, while ovaries expressed cyp19a1a and sox9b, but not amh. In adult testes, amh and sox9a were expressed in presumptive Sertoli cells. In adult ovaries, amh and cyp19a1a were expressed in granulosa cells surrounding the oocytes, and sox9b was expressed in a complementary fashion in the ooplasm of oocytes. The observed expression patterns of amh, sox9a, sox9b, and cyp19a1a in zebrafish correspond to the patterns expected if their regulatory interactions have been conserved with mammals. The finding that zebrafish sox9b and sox8 were not co-expressed with amh in oocytes excludes the possibility that amh expression in zebrafish granulosa cells is directly regulated by either of these two genes.     

Synonymous Codon Usage Bias and Overexpression of a Synthetic Gene Encoding Interferon α2b in Yeast

To achieve higher level expression of Interferon α2b(IFN-α2b)in methylotrophic yeast(Pichia pastoris),a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P.pastoris and optimized G C content.The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA,and then integrated into P.pastoris GS115 genome by electroporation.Multi-copy integrants in the Mut recombinant P.pastoris strain were screened by high concentrations of Zeocin.120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods.In addition,Western blot analysis showed that the recombinant proteins had immunogenicity.The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/VSV system,which was 3.3×105 IU/mL.     

Synonymous codon usage bias and overexpression of a synthetic gene encoding Interferon α2b in yeast

To achieve higher level expression of Interferon α2b (IFN-α2b) in methylotrophic yeast (Pichia pastoris), a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P. pastoris and optimized G+C content. The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA, and then integrated into P. pastoris GS115 genome by electroporation. Multi-copy integrants in the Mut⁺ recombinant P. pastoris strain were screened by high concentrations of Zeocin. 120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods. In addition, Western blot analysis showed that the recombinant proteins had immunogenicity. The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/ VSV system, which was 3.3×10⁵ IU/mL. Foundation items: The National ‘973’ Basic Research Program (2002CB111302); The National Natural Science Foundation of China (30370807)     

Changes in Thermostability of Photosystem Ⅱ and Leaf Lipid Composition of Rice Mutant with Deficiency of Light-harvesting Chlorophyll a/b Protein Complexes

We studied the difference in thermostability of photosystem Ⅱ （PSII） and leaf lipid composition between a T-DNA insertion mutant rice （Oryza sativa L.） VG28 and its wild type Zhonghuau. Native green gel and SDS-PAGE electrophoreses revealed that the mutant VG28 lacked all light-harvesting chlorophyll a/b protein complexes. Both the mutant and wild type were sensitive to high temperatures, and the maximal efficiency of PSII photochemistry （FJ Fm） and oxygen-evolving activity of PSII in leaves significantly decreased with increasing temperature. However, the PSII activity of the mutant was markedly more sensitive to high temperatures than that of the wild type. Lipid composition analysis showed that the mutant had less phosphatidylglycerol and sulfoquinovosyl diacylglycerol compared with the wild type. Fatty acid analysis revealed that the mutant had an obvious decrease in the content of 16：1t and a marked increase in the content of 18：3 compared with the wild type. The effects of lipid composition and unsaturation of membrane lipids on the thermostability of PSII are discussed.     

Synthesis and moisture absorption and retention activities of a carboxymethyl and a quaternary ammonium derivative of α,α-trehalose

Carboxymethyl α,α-trehalose (CMT) and a quaternary ammonium derivative of α,α-trehalose (QT) were successfully prepared, and their moisture absorption and retention activities were assessed. Results showed that both CMT and QT had better moisture absorption abilities at 43% and 81% relative humidity (RH) than α,α-trehalose. In addition, the two α,α-trehalose derivatives had better moisture retention abilities than α,α-trehalose under three humidity conditions: 81% RH, 43% RH, and under dry conditions. Therefore, carboxymethylation and quaternarization could improve the moisture absorption and retention abilities of α,α-trehalose. CMT and QT showed better moisture absorption ability and moisture retention ability than that of hyaluronan (HA), and could potentially find a use as moisture retention ingredient, for example, in cosmetics.