Papers by Romeu Guimaraes
(1) The logic of the living is the metabolic flow that is embedded in the universal and geochemic... more (1) The logic of the living is the metabolic flow that is embedded in the universal and geochemical flows. (2) At the origins of the genetic code, there is (proto)tRNA Dimer-Directed Polymerization [constitution of (proto)tRNA is not known]. (2a) The flow is slow because syntheses are bi-directional. Dimers are proto-ribosomes: structures that hold tRNAs together and propitiate the transferase reaction. (2b) (proto)tRNAs in the dimers are complementary, equivalent, superposed, coherent. ● An anticodon is at the same time codon for the other ● Products grow at both (proto)tRNAs. (3) Mechanism: Peptide products that are capable of (proto)tRNA binding and stabilization, without disrupting their activities, establish a self-referential self-stimulatory nucleoprotein production system, at the birth of cells. (4) Decoherence: Separation of the members of dimers was provoked by, among other possible interferences (e. g., proteins), intromission of the mRNA strings, which may have originated from enchaining of segments of the (proto)tRNAs (5) At translation (better, transliteration), Ribosome-Directed Polymerization is directional and the flow is fast. Genetic strings (mRNA) are scanned by laterally associated couples (instead of dimers of tRNAs) that enchain the carried amino acids into proteins.
Brazilian Journal of Medical and Biological Research
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Hospital (Rio de Janeiro, Brazil)
Revista da Associação Médica de Minas Gerais
ABSTRACT
Medicina cutánea ibero-latino-americana
ABSTRACT
Proteins maintain living systems in low entropy states, allowing the existence of life, as well a... more Proteins maintain living systems in low entropy states, allowing the existence of life, as well as cognitive and affective processes. They allow information patterns, internally or externally available to living individuals, to shape their morphology, physiology and behavior. Proteins make possible these processes and the genome makes possible the production of proteins, but they are not the substrate where the essential processes of life occur. We propose that this substrate is composed of signaling ionic (calcium, sodium, potassium) solutions, located in muscles, neurons, glia and extracellular space. Ionic currents and waves, controlled by macromolecular mechanisms, are proposed to constitute the biological medium for life.
Genetic code structure and evolution was studied through anticodonic principal dinucleotides (pDi... more Genetic code structure and evolution was studied through anticodonic principal dinucleotides (pDiN; central to 3’ base). Hydropathy correlation between amino acids and pDiN identified aminoacyl-tRNA synthetases (aRS) class 1 with Mx pDiN (mixed; RY, YR), aRS2 with Ho pDiN (homogeneous; RR, YY). The central, followed by the 3’ base, defined anticodonic pairing. The matrix diagonal structure was centered on the eight axial boxed of homodinucleotides (AA:UU, GG:CC) and self-complementary dinucleotides (AU:UA, GC:CG), with G and C cores and A and U tips, prototypes of the Ho and Mx pDiN sectors and quadrants, and completed with the eight non-axial boxes (central R : central Y): Ho, AG:UC, GA:CU, and Mx, AC:UG, GU:CA. Deviants from the aRS class – pDiN rule were five charging systems: aRS1-Ho (LeuAG:UCGlu) and aRS2-Mx (AlaGC, ThrGU, HisUG). The complexity of boxes was described through two rules: pDiN base composition of axial boxes, cores being simple and tips complex; precedence of pur...
Life is an abstract concept describing properties of cells, concrete objects. Sustainability of a... more Life is an abstract concept describing properties of cells, concrete objects. Sustainability of a living system is proposed to be important from the beginning, so that some endogenous protometabolism characterized protocells: “Life is the process manifested by individualized evolutionary metabolic systems.” Development of memory centers added the properties of self-production and formation of lineages, the genetic code being the landmark of the first biological population. Nucleic acids became genes for proteins that conferred stability to the nucleoproteic system. First genetic modules corresponded to peptides with coil and turn conformations, intrinsically stable and producing cognate self-referential interactions, binding to and stabilizing the nucleic acids participating in their generation.
Illicit drug users admitted in psychiatric hospital were studied, totaling 406 patients, 382 (94%... more Illicit drug users admitted in psychiatric hospital were studied, totaling 406 patients, 382 (94%) males. Their demographic and epidemiologic characteristics, and information on types of drugs, age at start of usage, patterns and routes of intake were obtained through structured anamnestic instrument. Illicit drug usage was much greater among men than among women during the same period. About half of the patients, of both sexes, were below 20, and 80% below 30 years of age. Most prevalent was the usage of crack, singly or associated with marijuana: 37.2% and 25.7%, respectively, among men; 58.3% and 29.2%, respectively, among women. Monodrug users were 207 (51%) and of polydrug 199 (49%), the former kind being slightly more frequent among females. Daily amounts consumed were up to 15g of crack, by 98.6% of users; 10g of marijuana, by 96.2% of users; and 5g of cocaine, by 91.7% of users. Consumption of crack and cocaine were significantly higher in males than in females. Only crack u...
A guided leisure stroll along the Peracanga Beach and neighboring sites, intending to raise atten... more A guided leisure stroll along the Peracanga Beach and neighboring sites, intending to raise attention in the visitor to how beautiful can the small everyday common environment be when closely observed, with care and tenderness. Illustrations though the attentive look of both the cartoonist and the scientist add humor to description. It is hoped that a small history told by the owls that once inhabited freely a corner of Peracanga could inspire conservationist feelings. In Portuguese, 4 pages
A complete review with extensive updating is offered on the self-referential model for the format... more A complete review with extensive updating is offered on the self-referential model for the formation of the genetic code. It spans from the first abstract (1996) to the last published paper (2012) and adds a concerted interpretation of all data utilized so far. In the webinar I concentrate on the aspects highlighting that the encoding process is regionalized with respect to the triplet constitution, which leads immediately to some degree of minimization of the consequences of errors.
In the genetic code matrix, amino acids with similar properties are attributed to codes also simi... more In the genetic code matrix, amino acids with similar properties are attributed to codes also similar to each other (regionalization, clustering). It has been thought that this property would have been selected for after (optimization) trials of amino acid allocations to different triplets, the fitness measure being minimization of the consequences to protein functions of mutational or translational errors. The Self-Referential Model (SRM) for the formation of the code says that this property derives from two mechanisms. (a) Formation of sets of codes for the same amino acid (degeneracy) comes from the synthetase (aRS)-tRNA recognition mechanisms of encoding/decoding. These obey the wobble + principal dinucleotide (pDiN) structure, which is also found in the ribosomal decoding quality control site. The aRS-tRNA correspondences start tetracodonic (simple box, 1 pDiN/1 amino acid); this wide wobbling may be conserved (GPATV) or expanded to hexacodonic (SLR). When a box becomes complex ...
Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life, Jan 14, 2015
The distribution of the triplet to amino acid correspondences in the genetic code matrix contains... more The distribution of the triplet to amino acid correspondences in the genetic code matrix contains blocks of similarity. There are (a) groups of similar triplets coding for the same amino acid, which is called code degeneracy, and (b) clusters of similar amino acids corresponding to similar triplets. Processes that led to this regionalization have been investigated through a variety of perspectives but no consensus has been reached and no model has been convincing enough to drive experimental tests. Most traditional has been the hypothesis that the code was derived from the standard evolutionary processes of testing variations in the correspondences through the fitness measure of reaching distributions in the matrix space in an optimal manner so that the effects of mutations on protein phenotypes would be minimized, that is, with reduction of the intensity or of the deviant quality of the functional alterations associated with variations. In contrast, the self-referential model for t...
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Papers by Romeu Guimaraes