The caingang revisited: Blood genetics and anthropometry

A total of 248 individuals belonging to four populations of Caingang Indians from southern Brazil were stuided in relation to 23 genetic systems that are expressed in blood and one manifested on saliva. These results were compared with those obtained in 400 members of these same communities that were subjected to 11 body measurements. Nine polymorphic loci (MNSs, P, Rh, Duffy, Diego, Hp, PGM₁, ESD, and Gc) were chosen for the calculation of the genetic distances between the four populations, which were compared with Mahalanobis's D² differences. The two sets of values proved to be intercorrelated but neither showed a relationship with the geographic distances separating the four communities. The Caingang were previously classified linguistically as Gê, and they show several affinities with the Gê tribes, both when hematological, and morphological, characteristics are considered. A variant PGD phenotype is also described, showing a curious storage effect.     

Gc and transferrin isoelectrofocusing subtypes among Brazilian Indians

A total of 397 persons living in six villages of three Brazilian Indian tribes were studied in relation to the Gc subtypes. The corresponding gene frequencies are more similar between the Gorotire and Caingang than between the Gorotire and the Krahó, despite the considerable geographical distance that separates the villages of these two first tribes and their lignuistic differentiation. An uncommon variant pattern (1C7) was observed in eight Gorotire Indians; it had been described for the first time in a Tibetan sample, furnishing additional evidence on the Asiatic origin of these Indians. The distinct Gc subtype frequencies observed in our main ethnic groups provide an important new tool for anthropological analyses. Tf subtypes were studied among the Caingang only. The frequencies of Tf^C1 and Tf^C2 are similar to those obtained by other researchers in Hessen, Germany.     

Carbonic anhydrases in plants and algae

Carbonic anhydrases catalyse the reversible hydration of CO₂, increasing the interconversion between CO₂ and HCO₃⁻ + H⁺ in living organisms. The three evolutionarily unrelated families of carbonic anhydrases are designated α-, β-and γ-CA. Animals have only the α-carbonic anhydrase type of carbonic anhydrase, but they contain multiple isoforms of this carbonic anhydrase. In contrast, higher plants, algae and cyanobacteria may contain members of all three CA families. Analysis of the Arabidopsis database reveals at least 14 genes potentially encoding carbonic anhydrases. The database also contains expressed sequence tags (ESTs) with homology to most of these genes. Clearly the number of carbonic anhydrases in plants is much greater than previously thought. Chlamydomonas, a unicellular green alga, is not far behind with five carbonic anhydrases already identified and another in the EST database. In algae, carbonic anhydrases have been found in the mitochondria, the chloroplast thylakoid, the cytoplasm and the periplasmic space. In C₃ dicots, only two carbonic anhydrases have been localized, one to the chloroplast stroma and one to the cytoplasm. A challenge for plant scientists is to identify the number, location and physiological roles of the carbonic anhydrases.     

Polymorphisms of CYP1a1, CYP2e1, GSTM1, GSTT1, and TP53 genes in Amerindians

Polymorphisms at the TP53, cytochrome P‐450 (CYP), and glutathione S‐transferase (GST) genes are related to cancer susceptibility and present high diversity in allele frequencies among ethnic groups. This study concerns the CYP2E1, GSTM1, and GSTT1 polymorphisms in seven Amerindian populations (Xavante, Guarani, Aché, Wai Wai, Zoró, Surui, and Gavião). Polymorphic sites at CYP1A1 and TP53 were also studied in the Aché and Guarani tribes and compared with previous results about these systems already obtained in the other populations. The CYP2E1*5B haplotype showed, respectively, the highest and the lowest frequencies already observed in human groups. High frequencies of CYP1A1*2A and CYP1A1*2C alleles and mostly low values of GSTM1*0/*0 and GSTT1*0/*0 genotypes were observed. These data may be interpreted as being due to genetic drift or selection for these high‐frequency CYP1A1 alleles and against GST null genotypes during America's colonization. Intrapopulation diversity varied from 0.19 (Guarani) to 0.38 (Surui), and 90% of the total diversity was due to the variability within populations. The relationships between these Amerindians and with other ethnic groups were evaluated based on D_A distances and the neighbor‐joining method. Low correlation was observed between genetic relationships and geographic distances or linguistic groups. In the TP53 comparison with other ethnic groups, Amerindians clustered together and then joined Chinese populations. The cluster analysis seems to indicate that the Aché tribe might descend from a Gê group that could have first colonized that Paraguayan region, but had also assimilated some amount of the Guarani gene pool, maybe through intertribal admixture. Am J Phys Anthropol 119:249–256, 2002. © 2002 Wiley‐Liss, Inc.     

Intra and intertribal genetic variation within a linguistic group: The Ge-speaking Indians of Brazil

A total of 562 individuals living in four villages of two Brazilian Indian tribes (Cayapo and Krahó) was studied in relation to blood groups ABO, MNSs, P, Rh, Lewis, Duffy, Kidd and Diego; haptoglobin, Gc, acid phosphatase and phosphoglucomutase types. These results were compared with those obtained previously among the Xavante, and the inhabitants of three other Cayapo villages, all of whom speak Ge languages; the ranges in gene frequencies observed in a representative series of South American Indians from all over the continent were also compiled. The Ge Indians are characterized by low frequencies ofR^z, medium frequencies ofR¹,R², R⁰, orr,Jk^a andPGM¹₁, and high frequencies ofGc² andACP^A when compared with other South American tribes. Genetic distance analyses based on six loci indicate that the intratribal variability observed among Cayapo is of the same order of magnitude as those obtained among the Xavante and Krahó, being much less pronounced than those observed among the Yanomama and Makiritare. The intertribal differences within this linguistic group are much less pronounced than those encountered among tribes that speak more differentiated languages.     

Carbonic anhydrase isozymes in American ponies and riding horses: A new polymorphic high-activity type isozyme

A study of the erythrocyte carbonic anhydrases of 219 American ponies and 76 riding horses has revealed the presence of five variants of the low-activity CA B isozyme and two variants of the high-activity CA C isozyme. The previously undetected variant of CA C was found only in the pony population and had an allele frequency of 8.9%. A family study of animals possessing the CA B variant A ₂ showed an unexpected high frequency of inheritance.     

Basic muscle protein,a third genetic locus isoenzyme of carbonic anhydrase?

Rabbit muscle cytosol extract contains a basic protein which represents about 2% of the total cytosol protein. It contains zinc in a 1:1 stoichiometric ratio, based on a molecular weight of 30,000, and it catalyzes the hydration of CO₂. It is immunochemically distinct from the high and low activity forms of rabbit blood carbonic anhydrase. It has comparatively poor activity as an esterase, and about 20% of the CO₂ hydratase activity of the rabbit blood low activity carbonic anhydrase. This CO₂ hydratase activity is not inhibited by acetazolamide at concentrations which totally inhibit the activity of the blood carbonic anhydrases. The evidence obtained to date, though circumstantial, suggests that this basic metalloprotein is a carbonic anhydrase derived from a third genetic locus with properties considerably different from those of the mammalian carbonic anhydrases heretofore identified.     

Heterogeneous origin of carbonic anhydrase activity of thylakoid membranes

Carbonic anhydrase activities of pea thylakoids as well as thylakoid fragments enriched either in Photosystem 1 (PS1-membranes) or Photosystem 2 (PS2-membranes) were studied. The activity of PS1-membranes if calculated on chlorophyll basis was much higher than the activity of PS2-membranes. Acetazolamide, a non-permeable inhibitor of carbonic anhydrases, increased carbonic anhydrase activity of PS2-membranes at concentrations lower than 10⁻⁶ M and suppressed this activity only at higher concentrations. A lipophilic inhibitor of carbonic anhydrases, ethoxyzolamide, effectively suppressed the carbonic anhydrase activity of PS2-membranes (I ₅₀ = 10⁻⁹ M). Carbonic anhydrase activity of PS1-membranes was suppressed alike by both inhibitors (I ₅₀ = 10⁻⁶ M). In the course of the electrophoresis of PS2-membranes treated with n-dodecyl-β-maltoside “high-molecular-mass” carbonic anhydrase activity was revealed in the region corresponding to core-complex of this photosystem. Besides, carbonic anhydrase activity in the region of low-molecular-mass proteins was discovered in the course of such an electrophoresis of both PS2-and PS1-membranes. These low-molecular-mass carbonic anhydrases eluted from corresponding gels differed in sensitivity to specific carbonic anhydrase inhibitors just the same as PS1-membranes versus PS2-membranes. The results are considered as evidence for the presence in the thylakoid membranes of three carriers of carbonic anhydrase activity. Published in Russian in Biokhimiya, 2006, Vol. 71, No. 5, pp. 651–659.     

Specific features of the system of carbonic anhydrases of alkaliphilic cyanobacteria

This review brings together our recent data on carbonic anhydrases of representatives of alkaliphilic cyanobacteria inhabiting soda lakes, which are considered as the relicts of the ancient terrestrial microbiota. The modern information about cyanobacterial carbonic anhydrases is based mainly on the study of model strains, such as Synechocystis and Synechococcus. Our results are compared with literature data. The role of carbonic anhydrases in the assimilation of inorganic carbon by cyanobacteria of soda lakes is discussed in terms of evolution of the CO₂-concentrating mechanism.     

Genetic studies of the Macushi and Wapishana Indians

Summary Blood samples from 509 Macushi and 623 Wapishana Amerindians of Northern Brazil and Southern Guyana have been analyzed with reference to the occurrence of rare variants and genetic polymorphisms of the following 25 systems: (i) Erythrocyte enzymes: acid phosphatase-1, adenosine deaminase, adenylate kinase-k, carbonic anhydrase-1, carbonic anhydrase-2, esterase A_1,2,3, esterase D, galactose-1-phosphate uridyltransferase, isocitrate dehydrogenase, lactate dehydrogenase, malate dehydrogenase, nucleoside phosphorylase, peptidase A, peptidase B, phosphoglucomutase 1, phosphoglucomutase 2, phosphogluconate dehydrogenase, phosphohexoseisomerase, triosephosphate isomerase and (ii) Serum proteins: albumin, ceruloplasmin, haptoglobin, hemoglobin A, hemoglobin A₂ and transferrin. Fifteen different rare variants were detected, involving 11 of these systems. In addition, a previously undescribed variant of ESA_1,2,3 which achieves polymorphic proportions in both these tribes is described. Excluding this variant, the frequency of rare variants is 1.1/1000 in 12510 determinations in the Macushi and 4.7/1000 in 15 396 determinations in the Wapishana. The ESA_1,2,3, polymorphism was not observed in 382 Makiritare, 232 Yanomama, 146 Piaroa, 404 Cayapo, 190 Kraho and 112 Moro. Irregularities in the intratribal distribution of this polymorphism in the Macushi and Wapishana render a decision as to the tribe of origin impossible at present. Gene frequencies are also given for previosly described polymorphisms of 5 systems: haptoglobin, phosphoglucomutase 1, erythrocyte acid phosphatase, esterase D, and galactose-1-phosphate-uridyl-transferase.Research supported by the National Science Foundation and the Energy Research and Development Administration.     

Binding thermodynamics of serotonin to rat-brain 5-HT1a, 5HT2a and 5-HT3 receptors

The thermodynamic parameters ΔG° , ΔH° and Δs° of the binding equilibrium of serotonin to 5-HT_1A, 5-HT_2A and 5-HT₃ rat-brain membrane receptors have been determined by means of affinity constant measurements at six temperatures in the range 0 –35 ° C and van't Hoff plots. At variance with 5-HT_1A and 5-HT₃, the binding at the 5-HT_2A receptors is strongly endothermic and entropy-driven. Comparison with the results obtained by other authors on 5-HT_2A receptors in rats and humans suggests that the observed differences can be explained by a single amino acid difference in the receptor sequence between these two species.     

FOUR PROTEIN POLYMORPHISMS IN PIGEON BRAIN EXTRACTS DETECTED BY TWO-DIMENSIONAL GEL ELECTROPHORESIS

Abstract— Proteins of the brain extracts of 85 individual pigeons (Columba livia) were mapped by two-dimensional gel electrophoresis. The method is a modification of O'Farrell 'S technique and separates proteins first by charge and then by molecular weight. There were three proteins, A, B and D which had each a variant form. The positions of these six proteins on the gel corresponded to the following pH values and molecular weight values: protein A₁, 6.4/43,000; A₂, 6.6/43,000; B₁, 5.7/41,000; B₂, 5.8/40,000; D₁, 6.2/22,000; D₂, 6.2/21,000. The variants are genetically determined, since protein A, B and D each occurred in three phenotypes (A₁, A₁A₂ and A₂; B₁, B₁B₂ and B₂; D₁, D₁D₂ and D₂) corresponding to the three possible genotypes. From the observed frequencies of the phenotypes the following allele frequencies were calculated: allele A₁, 72%; A₂, 28%; B₁, 15%; B₂, 85%; D₁, 74%; D₂, 26%. A fourth protein named C occurred in four different forms (C₁, 7.2/37,000; C₂, 7.2/36,000; C₃, 7.1/37,000; C₄, 7.1/36,000) and six phenotypes (C₁, C₁C₂, C₂, C₁C₃, C₂C₃ and C₄C₃). This polymorphism is also interpreted as being genetically determined. The four alleles coding for the four protein C forms had the following frequencies: allele C₁, 62%; C₂, 27%; C₃, 10.5%; C₄, 0.5%.     

Ethnohistory, intertribal relationships, and genetic diversity among Amazonian Indians

The influence of recent ethnohistorical factors on the microevolution of South American Indians has not been adequately evaluated by population geneticists. This makes difficult a reasonable interpretation of the present genetic structure of these groups. In this article the genetic diversity of 18 tribes of the Amazon and neighboring areas belonging to 3 linguistic groups (Tupi, Carib, and Gê) is analyzed in light of documentary sources about historical events, such as demographic changes, geographic movements, intertribal relationships, and marriage practices, that have taken place since the end of the eighteenth century. The high depopulation rate suffered by the Tupi groups (61.4% on average) is a probable factor conditioning the large intergroup genetic distances in this linguistic stock, for depopulation is a phenomenon associated with random genetic drift caused by a bottleneck effect. On the other hand, the relatively high similarity of the Gê and the Carib shows an association with two main factors: (1) reduced spatial dispersion of the Gê in the recent past, providing adequate conditions for within-stock gene flow, and (2) strong tradition of intergroup contacts among the Carib, frequently followed by genetic admixture and even fusion of groups, as verified for the Wayana and the Aparaí. The patterns of biologic variation of some Tupi tribes (Wai?pi, Emerillon, Parakan?, and Assurini) are better explained by historical and regional contingencies than by linguistic classification.     

Studies on blood groups and other genetic markers in forest Nentzi: Variation among the subpopulations

Summary A Samoyed-speaking group of fishers, hunters, and deer breeders numbering 1500 in total has been investigated. Seven territorial subgroups were examined with respect to 15 genetic systems. The presence of A₂, cde, C^wDe, Kp^a, AK², p^c, Gm^fb, and Gm^fnb genes or haplotypes in low or moderate frequencies was observed. An unexpected finding was a deleted Gm(-;n;gb) phenotype in three siblings.Significant local genetic heterogeneity was observed with regard to AB0, Rh, Tf, PGM₁, 6-PGD, and Gm systems. The summed genic heterogeneity was found to be highly significant ( ₁₃₂ ² =663.70, P< 0.001). Mean F_st was equal to 0.0228, reflecting variation among subpopulations dispersed in the forest-tundra area and living under conditions of partial isolation.     

Recombinant plant gamma carbonic anhydrase homotrimers bind inorganic carbon

Gamma carbonic anhydrases (γCA) are widespread in Prokaryotes. In Eukaryotes, homologous genes were found only in plant genomes. In Arabidopsis and maize, the corresponding gene products are subunits of mitochondrial Complex I.At present, only γCA homotrimers of Methanosarcina thermophila (CAM) show reversible carbon dioxide (CO₂) hydration activity. In the present work, it is shown that recombinant plant γCA2 could form homotrimers and bind . However, they are unable to catalyse the reversible hydration of CO₂.These results suggest that plant γCAs do not act as carbonic anhydrases but with a related activity possibly contributing to recycle CO₂ in the context of photorespiration.

Structured summary

MINT-7266044: gamma CA2 (uniprotkb:Q9C6B3) and gamma CA2 (uniprotkb:Q9C6B3) physically interact (MI:0914) by dynamic light scattering (MI:0038)MINT-7266036: gamma CA2 (uniprotkb:Q9C6B3) and gamma CA2 (uniprotkb:Q9C6B3) physically interact (MI:0914) by molecular sieving (MI:0071)     

Structural Basis for the Inhibition of Helicobacter pylori α-Carbonic Anhydrase by Sulfonamides

Periplasmic α-carbonic anhydrase of Helicobacter pylori (HpαCA), an oncogenic bacterium in the human stomach, is essential for its acclimation to low pH. It catalyses the conversion of carbon dioxide to bicarbonate using Zn(II) as the cofactor. In H. pylori, Neisseria spp., Brucella suis and Streptococcus pneumoniae this enzyme is the target for sulfonamide antibacterial agents. We present structural analysis correlated with inhibition data, on the complexes of HpαCA with two pharmacological inhibitors of human carbonic anhydrases, acetazolamide and methazolamide. This analysis reveals that two sulfonamide oxygen atoms of the inhibitors are positioned proximal to the putative location of the oxygens of the CO₂ substrate in the Michaelis complex, whilst the zinc-coordinating sulfonamide nitrogen occupies the position of the catalytic water molecule. The structures are consistent with acetazolamide acting as site-directed, nanomolar inhibitors of the enzyme by mimicking its reaction transition state. Additionally, inhibitor binding provides insights into the channel for substrate entry and product exit. This analysis has implications for the structure-based design of inhibitors of bacterial carbonic anhydrases.     

The multiplicity of roles for (bi)carbonate in photosystem II operation in the hypercarbonate-requiring cyanobacterium <Emphasis Type="Italic">Arthrospira maxima</Emphasis>

Arthrospira maxima is unique among cyanobacteria, growing at alkaline pH (<11) in concentrated (bi)carbonate (1.2 M saturated) and lacking carbonic anhydrases. We investigated dissolved inorganic carbon (DIC) roles within PSII of A. maxima cells oximetrically and fluorometrically, monitoring the light reactions on the donor and acceptor sides of PSII. We developed new methods for removing DIC based on a (bi)carbonate chelator and magnesium for (bi)carbonate ionpairing. We established relative affinities of three sites: the water-oxidizing complex (WOC), non-heme iron/Q_A^–, and solvent-accessible arginines throughout PSII. Full reversibility is achieved but (bi)carbonate uptake requires light. DIC depletion at the non-heme iron site and solvent-accessible arginines greatly reduces the yield of O₂ due to O₂ uptake, but accelerates the PSII–WOC cycle, specifically the S2→S3 and S3→S0 transitions. DIC removal from the WOC site abolishes water oxidation and appears to influence free energy stabilization of the WOC from a site between CP43-R357 and Ca²⁺.     

1-(2-Hydroxy-5-((trimethylsilyl)ethynyl)phenyl)ethanone based α,β-unsaturated derivatives an alternate to non-sulfonamide carbonic anhydrase II inhibitors,synthesis via Sonogashira coupling,binding analysis,Lipinsk’s rule validation

A novel series of silyl-yne containing chalcone derivatives 5a-5j was synthesized by exploiting Sonogashira coupling reaction and Claisen-Schimdt condensation reaction. The synthesized derivative were characterized by spectroscopic and elemental analysis. The selective inhibition of carbonic anhydrases is considered critical in the field of medicinal chemistry because carbonic anhydrases exits in several isoforms. Synthesized compounds were subjected to carbonic anhydrase –II assay. Except 5j, the other derivatives exhibited better potential than standard acetazolamide. Compound 5e was found to be potent derivative in the series with IC₅₀ value 0.054 ± 0.001 µM. Binding analysis revealed that most potent derivative 5e binds in the active site of CA-II and single π-π stacking interaction was observed between ring structure of ligand and Phe129 having bond length 4.90 Å. Pharmacokinetics elicited that compounds obey Lipinski’s rule and show significant drug score.     

Effects of Carbonic Anhydrase Inhibitors on Proton Exchange and Photosynthesis in Pea Protoplasts

At concentrations of 100–200 M, ethoxyzolamide, a lipophilic inhibitor of carbonic anhydrase, considerably (by 60%) inhibited light-induced CO₂-dependent oxygen evolution in pea protoplasts at the optimum concentration of inorganic carbon (100 M CO₂) in the medium. At the same concentrations of the inhibitor, electron transport in isolated pea thylakoids was inhibited only by 6–9%. Acetazolamide, a water-soluble inhibitor of carbonic anhydrase, affected neither the rate of CO₂-dependent O₂evolution in protoplasts nor electron transport in thylakoid membranes. A light-dependent proton uptake by protoplasts was demonstrated. At pH 7.2, the induction kinetics and the rate of proton uptake were similar to those for CO₂-dependent O₂evolution. The rate of proton uptake was decreased twofold by 1 mM acetazolamide. This fact agrees with the notion that a membrane-bound carbonic anhydrase is operative in the plasma membrane of higher plant cells. A mechanism of its functioning is suggested. Possible functions of carbonic anhydrases in the cells of C₃-plants are discussed.