PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “HEMOGLOBIN AND COMPOUNDS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources
PubMed2001

Screening and characterization of fructosyl-valine-utilizing marine microorganisms.

We describe the isolation of microorganisms utilizing fructosyl-amine (Amadori compound) from the marine environment and of fructosyl-amine oxidase from a marine yeast. Using fructosyl-valine (Fru-Val), a model Amadori compound for glycated hemoglobin, we isolated 12 microbial strains that grow aerobically in a minimal medium supplemented with Fru-Val as the sole nitrogen source. Among these strains, a yeast strain identified as Pichia sp. N1-1, produced a Fru-Val-oxidizing enzyme. The enzyme was purified in its active form, a single-polypeptide water-soluble protein of 54 kDa by gel electrophoresis, producing H(2)O(2) with the oxidation of Fru-Val. By its substrate specificity, the enzyme was categorized as a novel fructosyl-amine oxidase. This is the first study on the isolation of microorganisms utilizing fructosyl-amine in the marine environment and of fructosyl-amine oxidase from budding yeast.

Journal Article↗
PubMed1978

Studies on the thromboxane synthesizing system in human platelet microsomes.

The thromboxane synthesizing system from human platelets has been characterized by using arachidonic acid and prostaglandin endoperoxide as indirect and direct substrates. The synthesis of thromboxanes from either substrates catalyzed by the microsomal fraction was monitored by measuring the formation of thromboxane B2 immunoreactivity. Both hemoglobin and phenolic compounds were required for the maximal synthesis of thromboxane B2 from arachidonic acid but not from prostaglandin endoperoxide. Studies on the kinetics of the formation of thromboxane B2 from either substrates indicated that the synthesis of prostaglandin endoperoxide intermediate is the rate-limiting step in the overall production of thromboxanes from arachidonic acid. Effect of the microsomal protein concentrations on the rate of formation of thromboxane B2 showed concave upward relationship suggesting the possible involvement of endogenous stimulator(s) in thromboxane synthetase catalyzed reaction. A variety of compounds including sulfhydryl inhibitors, prostaglandin endoperoxide analog, prostaglandin antagonist, N-0164, and N-substituted imidazoles could directly inhibit the thromboxane synthetase, while nonsteroidal antiinflammatory drugs apparently affected the prostaglandin endoperoxide synthetase which catalyzes the synthesis of the immediate precursor of thromboxanes.

Arachidonic Acids↗
PubMed2003

Molecular cloning and expression of novel fructosyl peptide oxidases and their application for the measurement of glycated protein.

Fructosyl peptide oxidases, enzymes that are active against a model compound of glycated hemoglobin, N(alpha)-fructosyl valyl-histidine, were characterized. To identify the primary structure of fructosyl peptide oxidases, we have prepared cDNA libraries from Eupenicillium terrenum ATCC18547 and Coniochaeta sp. NISL9330. The coding regions, both fungal fructosyl peptide oxidases consisting of 1314-bp, were obtained with degenerated primers based on the amino acid sequences and specific primers by 3(') and 5(') RACE (rapid amplification of cDNA ends). By their sequence similarities and substrate specificities, fructosyl peptide oxidases and their homologs could be categorized into two groups: (A) enzymes that preferably oxidize alpha-glycated molecules and (B) enzymes that preferably oxidize epsilon-glycated molecules. We showed that recombinant fructosyl peptide oxidases could be used to detect protease-treated fructosyl-hexapeptide, a glycated peptide that is released from HbA(1C) by endoproteinase Glu-C, suggesting these enzymes could be useful for the enzymatic measurement of HbA(1C).

Amino Acid Oxidoreductases↗
PubMed1996

Perfluorocarbon emulsions and cardiopulmonary bypass: a technique for the future.

Artificial blood has been sought for a considerable period of time and two major lines of research have led to FDA testing of some possible compounds. The two major types of compounds are polymerized hemoglobin moieties and perfluorocarbon emulsions (PFC). Polymerized hemoglobin preparations have the ability to carry oxygen and release it in a manner similar to the oxyhemoglobin dissociation curve of whole blood. PFCs carry oxygen, nitrogen and carbon dioxide, as well as all other non-polar gases, by enhanced chemical solubility. Therefore, all dissolved gases are available for metabolic utilization and no sinusoidal release curve of oxygen is encountered. Early PFC emulsions had problems with toxicity of the emulsifier and were difficult to get into their emulsion for infusion. Furthermore they were very dilute in the active ingredient for gas transport. Today there are second generation PFCs becoming available that have a 40% concentration of the PFC and therefore the potential for gas transport is greatly increased. The PFC emulsions have a very small size, 0.1 microns, so the surface for gas exchange is massively increased as well as the potential increased for perfusion into areas of potentially sludged erythrocytes. Work with the PFCs has shown them now to be able to carry adequate oxygen to work as blood substitutes. They have shown protection from air embolism in a number of animal and end-organ models. What makes the PFCs unique is their ability to carry/absorb nitrogen and therefore protect from gas embolization. There are data in animal models showing significant cerebral protection in cardiopulmonary bypass models. The new PFCs should sometime in the not-too-distant future be tested in human bypass with assessments of neuropsychiatric dysfunction and stroke.

Animals↗
PubMed1999

Amino acid order in polymeric dipeptide surfactants: effect on physical properties and enantioselectivity.

The effect of amino acid order on chiral selectivity in polymeric dipeptide surfactants, as well as the physical properties of the surfactants, is investigated. An understanding of enantioselectivity of such dipeptide surfactants is crucial to the design of more efficient polymeric surfactants and has implications in other areas of research such as enantioselective interactions of amino acid based compounds (i.e., enzymes, hemoglobin, antibodies, etc.). It should be noted that such polymeric surfactants are not easily crystallized. Therefore, in a manner similar to the study of proteins, fluorescence spectroscopy is a powerful tool used to study the structure-function relationship of these polymeric surfactants. The microenvironments inside the core of 18 polymeric surfactants were characterized using the environmentally sensitive probes pyrene and 6-propionyl-2-(dimethylamino)naphthalene (Prodan). The surfactants examined in this study include all possible dipeptide combinations of the L-form of alanine, valine, and leucine and the achiral amino acid glycine (except glycine-glycine) as well as the single amino acid surfactants of alanine, valine, and leucine. The results of the fluorescent probe studies led to a proposed structure of the polymeric dipeptide surfactants in solution. The implications of the proposed structure for chiral selectivity were tested with two model atropisomers, (+/-)1,1'-bi-2-naphthol and (+/-)1,1'-bi-2-naphthyl-2,2'-diyl hydrogen phosphate, using capillary electrokinetic chromatography.

Amino Acid Sequence↗
PubMed2003

Identification of DNA adducts using HPLC/MS/MS following in vitro and in vivo experiments with arylamines and nitroarenes.

Arylamines and nitroarenes are suspected of playing a key role in chemical carcinogenesis. Therefore, the study of DNA adduct formation is an important step to determine the genotoxic potential of these compounds. Calf thymus DNA was modified in vitro by reaction with activated N-hydroxyarylamines: 2-chloroaniline (2CA), 4-chloroaniline (4CA), 2-methylaniline (2MA), 4-methylaniline (4MA), 2,4-dimethylaniline (24DMA), 2,6-dimethylaniline (26DMA), 2-aminobiphenyl (2ABP), 3-aminobiphenyl (3ABP), and 4-aminobiphenyl (4ABP). Female Wistar rats (n = 2) were given a single dose of the above arylamines and their analogous nitro derivatives by oral gavage and sacrificed after 24 h. Hepatic DNA and in vitro modified DNA were hydrolyzed enzymatically to individual 2'-deoxyribonucleosides. Adducts were determined using HPLC/MS/MS by comparison to synthesized standards. The hydrolysis efficiency was monitored by HPLC with UV detection. Each arylamine described above formed adducts to 2'-deoxyguanosine and 2'-deoxyadenosine after in vitro reaction with DNA. DNA adducts were found in rats dosed with 4ABP or with 4-nitrobiphenyl. DNA adducts were not detected in rats dosed with 2CA, 4CA, 2MA, 4MA, 24DMA, 26DMA, 2ABP, 3ABP, 2-chloronitrobenzene, 4-chloronitrobenzene, 2-nitrotoluene, and 4-nitrotoluene. All compounds formed hydrolyzable hemoglobin adducts. Therefore, biologically available N-hydroxyarylamines yielded hemoglobin adducts but not hepatic DNA adducts, except for 4ABP.

Amines↗
PubMed1998

The binding and utilization of hemoglobin by Prevotella intermedia.

Prevotella intermedia, a putative periodontopathic microorganism, requires iron for growth. Hemoglobin can be a major source of iron for bacterial growth in vivo since it is present in the crevicular fluid collected from periodontitis sites. Experiments studying the growth of P. intermedia in iron-depleted Todd-Hewitt broth supplemented with human hemoglobin showed that the bacteria were able to utilize human hemoglobin as a source of iron. The uptake of iron from hemoglobin by P. intermedia appears to be initiated by the binding of hemoglobin to the bacteria as shown by direct binding studies using 125I-labeled human hemoglobin. Scatchard analysis of saturation binding data revealed that 125I-labeled human hemoglobin had a dissociation constant (Kd) of 2.53 x 10(-8) M for the receptor on P. intermedia. Binding of labeled hemoglobin to P. intermedia was competitively inhibited by unlabeled human hemoglobin showing that the binding was specific. The ability of bovine hemoglobin, but not hemin or non-hemoglobin heme-containing compounds, to inhibit binding competitively suggested that the globin moiety of the hemoglobin molecule is recognized by the hemoglobin binding receptors.

Animals↗
PubMed2006

Association of Hb Shelby with Hb S in the south of Brazil.

We, herein, report the first observation of compound heterozygosity for hemoglobin Shelby and hemoglobin S identified in the south of Brazil. The variant hemoglobin was identified by isoelectric focusing (IEF), high performance liquid chromatography (HPLC) and DNA sequence analysis.

Brazil↗
PubMed1980

Iron acquisition by Neisseria meningitidis in vitro.

Assays employing iron-limited solid and liquid, defined and complex media were devised to test the iron requirements of Neisseria meningitidis. A variety of tests yielded no evidence for the secretion of a soluble iron-binding substance (siderophore) by the meningococci. The meningococci were unable to use iron bound to some common hydroxamate- and catechol-type siderophores or even compete with them for iron in the growth medium. A total of 20 strains of meningococci, differing widely in their virulence for mice, were similar in ability to acquire iron from a variety of iron-containing substances; the iron in such compounds as hog gastric mucin, citrate, hemoglobin, and myoglobin was easily acquired, whereas the iron in compounds such as ferrioxamine B, ferrichrome,ferritin, Imferon, cytochrome c, FePO4, and [Fe(OH)3]n was not readily available. No correlation was noted between the ability of particular strains to obtain iron from compounds and virulence in mice. Iron complexed or chelated with a number of metabolic organic acids, polyphosphates, and several synthetic polycarboxylic acids was readily available to all strains, even though some of the compounds used had high effective binding constants for iron and all were in 3- or 10-fold molar excess over the iron present. The addition of some of these iron-complexing substances (e.g., citrate and pyrophosphate) in iron-free form made many biologically important iron compounds that are normally inaccessible to the meningococci readily available.

Animals↗
PubMed1990

Evaluation of cysteine adduct formation in rat hemoglobin by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and related compounds.

The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) forms hemoglobin adducts in rats. Upon mild base treatment, 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) is released from this globin. HPB has been suggested as a dosimeter for exposure to and metabolic activation of tobacco-specific nitrosamines. The purpose of this study was 2-fold: (a) to determine whether cysteine adducts of NNK were precursors to HPB, and (b) to determine to what extent cysteine adducts accounted for the material bound to globin that is not released upon mild base hydrolysis. The chemistry of cysteine adduct formation was investigated by reacting N-acetyl-L-cysteine with three model compounds for pyridyloxobutylation by metabolically activated NNK: 4-(carbethoxynitrosamino)-1-(3-pyridyl)-1-butanone (1); 4-oxo-4-(3-pyridyl)-1-butylmethanesulfonate (2); and 4-iodo-1-(3-pyridyl)-1-butanone (3). Five adducts were isolated and characterized by their spectral properties and by independent syntheses: two diastereomers of N-acetyl-S-[1-methyl-3-oxo-3-(3-pyridyl)propyl]-L-cysteine (7a,b), N-acetyl-S-[4-oxo-4-(3-pyridyl)-1-butyl]-L-cysteine (9), and two diastereomers of N-acetyl-S-(2-[2-(3-pyridyl)]-2,3,4,5-tetrahydrofuranyl)-L-cystein e (11a,b). Only 11a,b produced HPB upon mild base treatment; however, the chemistry of this adduct did not support its role as a major precursor to HPB released upon base treatment of globin. The formation of adducts in rat hemoglobin was then examined by reacting it with tritium-labeled 1 [( 5-3H]1) or tritium-labeled 4-oxo-4-(3-pyridyl)-1-butyl p-toluenesulfonate [( 5-3H]4). The results demonstrated that the amino acids corresponding to 7a,b were present in hemoglobin reacted with [5-3H]1, accounting for 72% of the bound tritium. Amino acids corresponding to 9 were not detected in this globin. In contrast, hemoglobin reacted with [5-3H]4 contained the amino acid corresponding to 9 (15% of bound tritium), but not those corresponding to 7a,b. These results indicated that the alpha, beta-unsaturated ketone, 1-(3-pyridyl)-2-buten-1-one (5), played a major role in the hemoglobin binding of 1, but not of 4. Cysteine adducts were not detected in globin isolated from rats treated with [5-3H]NNK. The results of this study provide insights into the mechanisms of cysteine adduct formation in vitro by pryidyloxobutylating agents and indicate that these adducts are not formed in NNK-treated rats.

Animals↗
PubMed1980

Modification of hemoglobin by ninhydrin.

The Strecker degradation reaction was evaluated as a means of modifying hemoglobin in vitro, utilizing ninhydrin as a model compound. Ninhydrin led to modification of hemoglobin (when incubated with hemoglobin or red cells) at physiologic temperature and pH. Isoelectric focusing documented the formation of new hemoglobin bands, all with decreased (more negative) isoelectric points that hemoglobin A. Both alpha and beta chains were modified to an equal degree, although electrophoretic studies documented two modified species of alpha-chains and three modified species of beta-chains. Amino acid analysis of modified hemolysate following NaB3H4 reduction revealed peaks that coeluted with deaminated valine, epsilon-deaminated lysine, and a product with the guanidino group of arginine. The oxygen affinity of hemoglobin increased following its incubation with increasing concentrations of ninhydrin. These studies suggest that ninhydrin is representative of a class of carbonyl compounds that could be utilized to specifically modify that structure and function of hemoglobin variants.

Chemical Phenomena↗