Sampling the proteome by emerging single-molecule and mass-spectrometry methods

Mammalian cells have about 30,000-fold more protein molecules than mRNA molecules. This larger number of molecules and the associated larger dynamic range have major implications in the development of proteomics technologies. We examine these implications for both liquid chromatography-tandem mass spectrometry (LC-MS/MS) and single-molecule counting and provide estimates on how many molecules are routinely measured in proteomics experiments by LC-MS/MS. We review strategies that have been helpful for counting billions of protein molecules by LC-MS/MS and suggest that these strategies can benefit single-molecule methods, especially in mitigating the challenges of the wide dynamic range of the proteome. We also examine the theoretical possibilities for scaling up single-molecule and mass spectrometry proteomics approaches to quantifying the billions of protein molecules that make up the proteomes of our cells.Comment: Recorded presentation: https://youtu.be/w0IOgJrrvN

Relationships between Lower-body Power, Sprint and Change of Direction Speed among Collegiate Basketball Players by Sex

International Journal of Exercise Science 15(6): 974-984, 2022. The purpose of this study was to determine if significant relationships exist between absolute and relative lower-body power and selected measures of speed among male and female collegiate basketball players. Archived performance testing data from 29 (male = 14; female = 15) NCAA division II collegiate basketball players were used for this analysis. These measures included lane agility, 10-yard sprint, and shuttle run time (sec). A Pearson’s correlation coefficient was used to determine if significant relationships existed between measures of lower-body power and linear sprint time, change of direction speed (CODS), and shuttle performance. Statistical significance was set a priori at p ≤ 0.05. A significant large correlation was found between absolute power and lane agility (r = 0.54, p = 0.05) among male players. No significant correlations were found between absolute or relative power for 10-yard sprint times, lane agility, or shuttle run performance (p \u3e 0.05). Females showed no significant correlations between relative power and lane agility (r = -0.25, p = 0.37) or 10-yard sprint (r = -0.47, p = 0.08), but did show a significant large correlation (r = -0.64, p = 0.01) between relative power and shuttle run performance. Generating high amounts of relative power is vital in intermittent team sports such as basketball. In particular, this study provided evidence that relative power in female collegiate basketball players is significantly related to shuttle run ability

Promoter Methylation of RASSF1A Associates to Adult Secondary Glioblastomas and Pediatric Glioblastomas

While allelic losses and mutations of tumor suppressor genes implicated in the etiology of astrocytoma have been widely assessed, the role of epigenetics is still a matter of study. We analyzed the frequency of promoter hypermethylation by methylation-specific PCR (MSP) in five tumor suppressor genes (PTEN, MGMT, RASSF1A, p14ARF, and p16INK4A), in astrocytoma samples and cell lines. RASSF1A was the most frequently hypermethylated gene in all grades of astrocytoma samples, in cell lines, and in adult secondary GBM. It was followed by MGMT. PTEN showed a slight methylation signal in only one GBM and one pilocytic astrocytoma, and in two cell lines; while p14ARF and p16INK4A did not show any evidence of methylation in primary tumors or cell lines. In pediatric GBM, RASSF1A was again the most frequently altered gene, followed by MGMT; PTEN, p14 and p16 showed no alterations. Lack or reduced expression of RASSF1A in cell lines was correlated with the presence of methylation. RASSF1A promoter hypermethylation might be used as a diagnostic marker for secondary GBM and pediatric GBM. Promoter hypermethylation might not be an important inactivation mechanism in other genes like PTEN, p14ARF and p16INK4A, in which other alterations (mutations, homozygous deletions) are prevalent

IAA : Información y actualidad astronómica (13)

Sumario : Las galaxias anfitrionas de los GRBs.-- Marte: una historia de descubrimientos.-- Programa Ramón y Cajal: ¿recuperación o catapulta de cerebros?.-- CHARLAS CON...Fernando Cornet.-- El problema de la distancia a las Pléyades.-- Un bólido sobre nuestras cabezas.-- Actividades IAA.-- Agenda.Esta revista se publica con la ayuda de la Acción Especial DIS 2003-10261-E del Programa Nacional de Difusión y divulgación de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.N

IAA : Información y actualidad astronómica (26)

Sumario : Estrellas de neutrones: furioso magnetismo.-- La astronomía en el arte.-- DECONSTRUCCIÓN Y otros ENSAYOS : Lo más frío del Universo.-- CIENCIA: PILARES E INCERTIDUMBRES : Los meteoritos “ordinarios”.-- ACTUALIDAD.-- ENTRE BASTIDORES : Las generaciones perdidas.-- HISTORIAS DE ASTRONOMÍA : El organista que descubrió Urano.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda FCT-08-0130 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica 2008.N

DETERMINACION DE LOS REQUERIMIENTOS DE PROTEINA Y ENERGIA DE JUVENILES DE PACO, Piaractus brachypomus ( PISCES CHARACIDAE)

Fueron formuladas seis dietas experimentales que contenían dos niveles de proteína bruta (27,4 % y 29,8 %) y tres niveles de energía digestible(2700, 2900 y 3100 kcal/Kg. de alimento) por cada nivel de proteína para determinar los requerimientos de proteínas y energía y la relación optima energía/proteínas para alevinos de paco en condiciones controladas. Las dietas fueron formuladas para contener dos niveles de metionina + cistina (0,95 % para 27,4 % de proteína y 1,03% para 29,8 % de proteína). Se utilizaron los siguientes ingredientes: harina de pescado torta de soya, maíz amarillo duro y polvillo de arroz, además de aditivos como premezcla de vitaminas y minerales, bentonita (ligante) y BHT (Antioxidante). El aceite de pescado sirvió para ajustar los niveles de energía requeridos. Las dietas experimentales fueron suministradas en triplicado a grupos de cuatro peces juveniles con pesos promedios de 179,45 +- 8,39 g., colocados en 18 estanques de fibra de vidrio de 300 litros de capacidad efectiva cada uno, alimentados con un flujo de agua proveniente del subsuelo con una temperatura de 26,08 +- 0,75 grados centígrados, oxígeno disuelto de 5,34 +- 0,82 mg/l y pH de 5,88 +- 0,16. Las dietas fueron suministradas ad líbitum dos veces por día, reajustadas cada dos semanas, durante noventa días. Con respecto a la ganancia de peso y retención de proteína corporal se encontraron diferencias. significativas (P<0.05) entre tratamientos. El análisis estadístico demostró que niveles mínimos de 29,8% de proteína bruta y 2700 kcal de energía digestible/Kg. de alimento son los requeridos por juveniles de paco en dietas de crecimiento para obtener una adecuada ganancia de peso y una eficiente retención de proteínas, con una relación energía digestibles/proteínas de 9,0 Kcal/g de proteínas