Studies toward a prebiotic protometabolism

Understanding the origin of life is one of the foremost challenges for science. Despite the immense diversity displayed by biology on the macroscopic scale, cellular biochemistry is at its most fundamental level remarkably uniform. Recognising the minimal elements of biochemistry required for a living system represents one task within origins of life research, whereas the other is understanding the organic chemistry which could have led to their spontaneous organisation on the abiotic Earth. Significant attention has been paid to the prebiotic generation and assembly of the components of nucleic acids resulting in the demonstration of important prebiotic syntheses and in the uncovering of various key problems which have seeded much informative discussion within the prebiotic community. However, experimental investigations into the assembly of key sets of ubiquitous metabolites have been comparatively lacking and will be necessary to assess the relevance of central metabolic pathways to the earliest stages in the development of life. Presented herein are investigations into the prebiotic chemistry of a selection of small molecules central to one of the most fundamental and highly conserved metabolic pathways found in biology; triose glycolysis. By utilising a prebiotically relevant method of specifically generating aldehyde-2-phosphates from simple sugar precursors, it has been shown that several intermediates common to glycolysis can be generated in high yield under mild, aqueous conditions in a simple step-wise sequence which culminates in the generation (for the first time under prebiotically relevant conditions) of the highest-energy organophosphate utilised by nature; phosphoenolpyruvate. Based on the demonstrated transformations, a potentially prebiotic network of glycolytic reactions is proposed, sharing common precursors and reaction conditions with important existing work within the field concerning the generation of nucleotides, amino-acids and lipids. The predisposition of hydroxy-aldehydes to glycolytically important transformations and the relationship of the proposed prebiotic network to extant glycolysis is discussed

Cancer health disparities in racial/ethnic minorities in the United States

There are well-established disparities in cancer incidence and outcomes by race/ethnicity that result from the interplay between structural, socioeconomic, socio-environmental, behavioural and biological factors. However, large research studies designed to investigate factors contributing to cancer aetiology and progression have mainly focused on populations of European origin. The limitations in clinicopathological and genetic data, as well as the reduced availability of biospecimens from diverse populations, contribute to the knowledge gap and have the potential to widen cancer health disparities. In this review, we summarise reported disparities and associated factors in the United States of America (USA) for the most common cancers (breast, prostate, lung and colon), and for a subset of other cancers that highlight the complexity of disparities (gastric, liver, pancreas and leukaemia). We focus on populations commonly identified and referred to as racial/ethnic minorities in the USA—African Americans/Blacks, American Indians and Alaska Natives, Asians, Native Hawaiians/other Pacific Islanders and Hispanics/Latinos. We conclude that even though substantial progress has been made in understanding the factors underlying cancer health disparities, marked inequities persist. Additional efforts are needed to include participants from diverse populations in the research of cancer aetiology, biology and treatment. Furthermore, to eliminate cancer health disparities, it will be necessary to facilitate access to, and utilisation of, health services to all individuals, and to address structural inequities, including racism, that disproportionally affect racial/ethnic minorities in the USA.Fil: Zavala, Valentina A.. University of California; Estados UnidosFil: Bracci, Paige M.. University of California; Estados UnidosFil: Carethers, John M.. University of Michigan; Estados UnidosFil: Carvajal Carmona, Luis. University of California at Davis; Estados UnidosFil: Coggins, Nicole B.. University of California at Davis; Estados UnidosFil: Cruz Correa, Marcia R.. Universidad de Puerto Rico; Puerto RicoFil: Davis, Melissa. No especifíca;Fil: de Smith, Adam J.. University of California; Estados UnidosFil: Dutil, Julie. Ponce Research Institute; Puerto RicoFil: Figueiredo, Jane C.. Cedars Sinai Medical Center; Estados UnidosFil: Fox, Rena. University of California; Estados UnidosFil: Graves, Kristi D.. University Of Georgetown; Estados UnidosFil: Gomez, Scarlett Lin. University of California; Estados UnidosFil: Llera, Andrea Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Neuhausen, Susan L.. No especifíca;Fil: Newman, Lisa. No especifíca;Fil: Nguyen, Tung. University of California; Estados UnidosFil: Palmer, Julie R.. National Institutes of Health; Estados UnidosFil: Palmer, Nynikka R.. University of California; Estados UnidosFil: Pérez Stable, Eliseo J.. National Institutes of Health; Estados UnidosFil: Piawah, Sorbarikor. University of California; Estados UnidosFil: Rodriquez, Erik J.. National Institutes of Health; Estados UnidosFil: Sanabria Salas, María Carolina. Instituto Nacional de Cancerología; ColombiaFil: Schmit, Stephanie L.. University of Southern California; Estados UnidosFil: Serrano Gomez, Silvia J.. Instituto Nacional de Cancerología; ColombiaFil: Stern, Mariana Carla. University of Southern California; Estados UnidosFil: Weitzel, Jeffrey. No especifíca;Fil: Yang, Jun J.. St. Jude Children’s Research Hospital; Estados UnidosFil: Zabaleta, Jovanny. No especifíca;Fil: Ziv, Elad. University of California; Estados UnidosFil: Fejerman, Laura. University of California; Estados Unido

Prebiotic synthesis of phosphoenol pyruvate by α-phosphorylation-controlled triose glycolysis

Phosphoenol pyruvate is the highest-energy phosphate found in living organisms and is one of the most versatile molecules in metabolism. Consequently, it is an essential intermediate in a wide variety of biochemical pathways, including carbon fixation, the shikimate pathway, substrate-level phosphorylation, gluconeogenesis and glycolysis. Triose glycolysis (generation of ATP from glyceraldehyde 3-phosphate via phosphoenol pyruvate) is among the most central and highly conserved pathways in metabolism. Here, we demonstrate the efficient and robust synthesis of phosphoenol pyruvate from prebiotic nucleotide precursors, glycolaldehyde and glyceraldehyde. Furthermore, phosphoenol pyruvate is derived within an α-phosphorylation controlled reaction network that gives access to glyceric acid 2-phosphate, glyceric acid 3-phosphate, phosphoserine and pyruvate. Our results demonstrate that the key components of a core metabolic pathway central to energy transduction and amino acid, sugar, nucleotide and lipid biosyntheses can be reconstituted in high yield under mild, prebiotically plausible conditions

Scientific assessment of the use of sugars as cigarette tobacco ingredients: A review of published and other publicly available studies

Sugars, such as sucrose or invert sugar, have been used as tobacco ingredients in American-blend cigarettes to replenish the sugars lost during curing of the Burley component of the blended tobacco in order to maintain a balanced flavor. Chemical-analytical studies of the mainstream smoke of research cigarettes with various sugar application levels revealed that most of the smoke constituents determined did not show any sugar-related changes in yields (per mg nicotine), while ten constituents were found to either increase (formaldehyde, acrolein, 2-butanone, isoprene, benzene, toluene, benzo[k]fluoranthene) or decrease (4-aminobiphenyl, N-nitrosodimethylamine, N-nitrosonornicotine) in a statistically significant manner with increasing sugar application levels. Such constituent yields were modeled into constituent uptake distributions using simulations of nicotine uptake distributions generated on the basis of published nicotine biomonitoring data, which were multiplied by the constituent/nicotine ratios determined in the current analysis. These simulations revealed extensive overlaps for the constituent uptake distributions with and without sugar application. Moreover, the differences in smoke composition did not lead to relevant changes in the activity in in vitro or in vivo assays. The potential impact of using sugars as tobacco ingredients was further assessed in an indirect manner by comparing published data from markets with predominantly American-blend or Virginia-type (no added sugars) cigarettes. No relevant difference was found between these markets for smoking prevalence, intensity, some markers of dependence, nicotine uptake, or mortality from smoking-related lung cancer and chronic obstructive pulmonary disease. In conclusion, thorough examination of the data available suggests that the use of sugars as ingredients in cigarette tobacco does not increase the inherent risk and harm of cigarette smoking

A Chemist’s Perspective on the Role of Phosphorus at the Origins of Life

The central role that phosphates play in biological systems, suggests they also played an important role in the emergence of life on Earth. In recent years, numerous important advances have been made towards understanding the influence that phosphates may have had on prebiotic chemistry, and here, we highlight two important aspects of prebiotic phosphate chemistry. Firstly, we discuss prebiotic phosphorylation reactions; we specifically contrast aqueous electrophilic phosphorylation, and aqueous nucleophilic phosphorylation strategies, with dry-state phosphorylations that are mediated by dissociative phosphoryl-transfer. Secondly, we discuss the non-structural roles that phosphates can play in prebiotic chemistry. Here, we focus on the mechanisms by which phosphate has guided prebiotic reactivity through catalysis or buffering effects, to facilitating selective transformations in neutral water. Several prebiotic routes towards the synthesis of nucleotides, amino acids, and core metabolites, that have been facilitated or controlled by phosphate acting as a general acid–base catalyst, pH buffer, or a chemical buffer, are outlined. These facile and subtle mechanisms for incorporation and exploitation of phosphates to orchestrate selective, robust prebiotic chemistry, coupled with the central and universally conserved roles of phosphates in biochemistry, provide an increasingly clear message that understanding phosphate chemistry will be a key element in elucidating the origins of life on Earth