Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “haptoglobin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1979

Canine haptoglobin: a unique haptoglobin subunit arrangement.

1. Isolated canine haptoglobin behaved identically to the alpha 2 beta 2 structure typical of human haptoglobin type 1-1 on alkaline polyacrylamide gel electrophoresis and on gel filtration. 2. In the presence of urea or sodium dodecyl sulphate canine haptoglobin dissociated into alpha beta subunits that separated into alpha and beta chains after reduction with 2-mercaptoethanol. 3. Compositional analysis identified one less half-cystine in canine alpha chain when compared to human alpha 1 chain. 4. These results provide evidence that there is no inter alpha chain disulphide in canine haptoglobin comparable to the alpha 1 20-alpha 1 20 disulphide in human haptoglobin that links the two alpha beta subunits.

Amino Acids↗
PubMed1979

Identification of haptoglobin in chicken serum and specificity of the chicken haptoglobin-hemoglobin complex formation.

1. The presence of haptoglobin in chicken serum has been demonstrated by three different techniques: gel filtration, cellulose acetate electrophoresis and fluorescence quenching. 2. Chicken haptoglobin shows a narrow species specificity; it binds only avian and reptilian but not mammalian hemoglobins. 3. Haptoglobin seems to have been subjected to profound changes during the course of evolution.

Animals↗
PubMed1977

Influence of modifications of physicochemical and biological properties of haptoglobin. VII. Immunochemical reactivity of haptoglobin with modified tyrosine residues.

Tyrosine residues in human haptoglobin (Hp) type 2-1 were modified by treatment with various amounts of N-acetylimidazole, iodine or tetranitromethane. Rabbit antisera directed against native Hp, Ac-Hp, 1-Hp and NO2-Hp in cross-reactions by immunoprecipitation showed serologic identify of native Hp and most of the modified derivatives, with the exception of derivatives modified by means of a high excess of N-acetylimidazole, which showed partial identity with remaining preparations, irrespective of the antiserum used. The results indicate that tyrosine residues play no essential role in the immunochemical reactivity of haptoglobin.

Acetylation↗
PubMed1978

Studies on the structure of haptoglobin and the haptoglobin-haemoglobin complex by spin and fluorescence labelling.

Human haptoglobin (Hp) of the 1-1 type incorporated one spin or fluorescence marker per molecule; the markers were found in the beta chain. Formation of the complex between spin-labelled Hp and haemoglobin or antibody caused conformational changes in the Hp molecular, evidenced by increased participation in the electron paramagnetic resonance spectrum of the component bound with the slowly rotating marker. From fluorescence-labelled Hp, the beta chain was isolated and cleaved by CNBr; only in one of the obtained peptides, one out of 4 histidine residues was modified with the marker.

Cyanogen Bromide↗
PubMed1979

[Further investigations concerning the reaction between haptoglobin and T4-antigen-carrying streptocci (author's transl)].

The median level of haptoglobin types 2-2 and 2-1 was found to be proportional to the agglutination titer of T4 antigen-carrying streptococci (Fig. 1). This relationship need not exist in individual sera since, as seen from Table 1, high agglutination titers may be caused by sera with low levels of haptoglobin. Thus the agglutination reaction might depend not only on the quantity of haptoglobin but also on other factor(s) (at least in individual serum samples). - On the other hand, different agglutination titers did not correlate with the quantity of T4 antigen either. A strain of Strep. pyogenes, type 60, was agglutinated at high titers by sera with a high level of haptoglobin in spite of its low ability to absorb haptoglobin. This was in contrast to a strain of group G (20488) which had a high capacity both to become agglutinated and to absorb haptoglobin (Table 2). Absorption of haptoglobin by affinity chromatography decreased the agglutination titer for T4 streptococci. - The reaction between haptoglobin and T4-streptocci did not fix complement. No differences were found between sera of haptoglobin types 1-1, 2-1, and 2-2 with respect to the amount of C, C3, C4, and C3A, respectively (Tables 3-5).

Agglutination Tests↗
PubMed1979

Microheterogeneity of mammalian haptoglobins in isoelectric focusing.

1. Human haptoglobin type 1-1, porcine haptoglobin, and equine haptoglobin were isolated and purified. 2. These haptoglobins were similar in polyacrylamide gel electrophoresis and in subunit structure but showed microheterogeneity in isoelectric focusing. 3. Isoelectric points of human haptoglobin as determined with photopolymerized gels were found to be 4.03-4.24, of porcine haptoglobin 4.0-4.30, and of horse haptoglobin 3.80-4.15, respectively. 4. Results obtained with chemically polymerized gels were 0.08-0.3 pH units higher. 5. Examined haptoglobins differed also in the ability of complex formation with hemoglobin, in sialic acid content and in antigenic specificity.

Animals↗
PubMed1979

[Haptoglobin levels in premature infants].

A group of 30 preterm babies with no evidence of infections was investigated. They were separated in 3 groups according to the gestational age. In the first group, which included babies 28 to 32 weeks of gestational age, haptoglobin was detected in 5, but in 3, levels were under 25 mg/dl. In the second group, which consisted of babies of 33 to 36 weeks of gestational age, haptoglobin was detected in 6 infants, with levels less than 25 mg/dl in 3. Finally, in the group of babies of 37 to 40 weeks, haptoglobin was presented in 7. Haptoglobin was detected in 18 infants, which means in 60% of patients. Levels of haptoglobin were lower in babies of lower gestational age. Values obtained for haptoglobin levels in this study will be used in diagnostic purposes, for comparation with levels obtained in various pathological conditions.

Female↗
PubMed1977

[Relationship between haptoglobin types and group G streptococci (author's transl)].

A relationship was found between the haptoglobin types of human sera and the agglutinability of some strains of group G streptococci. Sera with the haptoglobin types Hp 2-2 and Hp 2-1 agglutinate these streptococci to high titers, from 1:200 up to more than 1:6400. On the other hand, the sera with haptoglobin type Hp 1-1 agglutinate not more than up to titers of 1:16 (mostly lower). Out of 102 strains of group G streptococci only 3 showed this characteristic phenomenon. This study was undertaken in order to elucidate whether the Hp 2-2 and Hp 2-1 proteins have antibody activity. Incubation of Hp 2-2 or Hp 2-1 sera with antihaptoglobin antisera or with anti-Hp 2-antiserum did not change the agglutinating activity but the haptoglobin was eliminated from the sera. Absorption of Hp 2-2 and Hp 2-1 sera with these group G streptococci lowered the titers significantly but the haptoglobins are detectable as in the non-absorbed sera. Sera with haptoglobin 1-1 contain an inhibitor. Mixing of Hp 2-2 and Hp 2-1 sera with high agglutinating titers with Hp 1-1 sera (low titers) was followed by a significant decrease of the titer.

Agglutination↗
PubMed1976

Studies on the binding of haemoglobin by haptoglobin using electrofocusing and gradient electrophoresis.

1. Gel electrofocusing followed by gel gradient electrophoresis separated the haptoglobins and their complexes with haemoglobin into characteristic two-dimensional patterns of protein bands. 2. Molecular weights of 107 000, 139 000 and 168 000 were obtained for the three bands seen after a purified preparation of haptoglobin type 1 was partially saturated with haemoglobin. This indicated that free haptoglobin, the intermediate haptoglobin-haemoglobin complex containing one half-haemoglobin and the saturated complex with two half-haemoglobins were present. 3. The three proteins showed considerable microheterogeneity and gave a number of isoelectric points in the pH ranges 4.58-4.77, 5.20-5.40 and 5.74-5.93, free haptoglobin type 1 being the lowest group. These ranges were all 0.15-0.30pH units lower if other values were taken for the isoelectric points of markers used to calibrate the pH gradient. 4. All three proteins were present over a wide range of haemoglobin concentrations, from 0.5% to 92% of that required for saturation. This would be expected if both binding sites have similar affinities for haemoglobin.

Binding Sites↗
PubMed1979

Is immunochemical determination of haptoglobin phenotype dependent?

Immunochemical methods have been used to determine the concentration of haptoglobins. The dependence on the phenotype was tested with highly purified Hp 2-1, Hp 2-2 and Hp 1-1, by immunonephelometry and radial immunodiffusion (RID). Measurements with three different instruments: automated immunonephelometer (AIP, Technicon), laser nephelometer (LN, Behring) and immunochemistry system (ICS, Beckman) were performed. For each type of apparatus antisera against a pool of haptoglobins were provided by the respective manufacturers. Some experiments were done with an antiserum to the haptoglobin heavy chain prepared in the laboratory. This study shows that haptoglobin determination depends neither on the physical geometry of the instruments or on the type of antiserum used in this work. In contrast, the data display a dependence on haptoglobin phenotype. When Hp 2-1, the most common phenotype, is taken as a standard, thd values obtained for Hp 2-2 are in good agreement with those obtained for Hp 2-1. However, the values obtained for Hp 1-1 are overestimated unless they are corrected by an experimental factor which has been determined in this study.

Haptoglobins↗
PubMed1979

A general affinity chromatographic method for preparing monospecific antibody to mammalian serum haptoglobin.

A general affinity chromatographic method for preparation of monospecific antibody to serum haptoglobin of any species is described. Hemoglobin prepared from the species to be immunized is coupled to an organomercurical substituted agarose gel support (Affi-Gel 501). The immobilized hemoglobin binds haptoglobin with great affinity and allows removal of other serum proteins by extensive washing. The haptoglobin-hemoglobin complexes are then specifically eluted by buffers containing dithiothreitol or other thiols and are further purified by chromatography on concanavalin A-agarose and Sephacryl S-200 columns. The pure complexes are very effective immunogens. Potent monospecific antisera to rabbit and to human haptoglobin have been prepared. The potential usefulness of affinity chromatography support media with specifically cleavable ligand sites in studies of haptoglobin and in other biological studies is discussed.

Animals↗
PubMed1979

Effects of obesity, total fasting and re-alimentation on L-thyroxine (T4), 3,5,3'-L-triiodothyronine (T3), 3,3',5'-L-triiodothyronine (rT3), thyroxine binding globulin (TBG), cortisol, thyrotrophin, cortisol binding globulin (CBG), transferrin, alpha 2-haptoglobin and complement C'3 in serum.

UNLABELLED: The effects of total fasting for 31 +/- 10 days followed by re-alimentation with an 800 calorie diet on thyroid function, i.e. T4,T3,rT3,RT3U (resin T3 uptake), and TSH, and on TBG levels in serum were studied sequentially in obese hospitalized patients (N=18). Additionally, cortisol, growth hormone, prolactin, parathyrin and free fatty acids were followed as hormonal and metabolic parameters, respectively. Further, CBG, transferrin, alpha 2-haptoglobin and complement C'3 were measured as representatives of other serum proteins. Results before fasting: T4, T3, TBG, cortisol, CBG, alpha 2-haptoglobin and complement C'3 of the obese patients were elevated when compared with healthy normal weight controls, whereas rT3, T4/TBG ratio, T3/TBG ratio, TSH, coritsol/cbg ratio, growth hormone, prolactin, parathyrin and transferrin of the obese group were normal. RT3U and fT4 index were decreased in the obese patients. Results during fasting: Significant decreases were observed during fasting for the following parameters -- T3, TBG, T3/TBG ratio, transferrin, alpha 2-haptoglobin complement C'3. rT3, T4/TBG ratio, RT3U, fT4 index and FFA increased. T4, tsh response to TRH stimulation, cortisol, CBG, cortisol/cbg ratio, parathyrin, growth hormone and prolactin did not change. Results during re-alimentation: T3, TBG, T3/TBG ratio, TSH response to TRH, transferrin, alpha 2-haptoglobin and complement C'3 increased. Conversely, fT3, RT3U, FFA, cortisol and cortisol/cbg ratio decreased whereas the other parameters did not change. CONCLUSIONS: 1) There is no evidence for primary hypothyroidism in obese patients during prolonged fasting and re-alimentation. 2) The rapid decrease of T3 and increase of RT3U after initiation of fasting are not fully explained by the observed slower decreases in TBG. 3) The alterations of T3, rT3 and RT3U resemble in their kinetics the changes in FFA levels. 4) Fasting reduced the levels of only certain serum proteins, interestingly TBG, transferrin, alpha 2-haptoglobin and complement C'3, all of which, except transferrin, are elevated in obesity. 5) The magnitude of the observed decreases does not suggest any clinically relevant deficiencies in serum proteins. 6) Re-alimentation reverses rapidly all observed changes.

Adult↗
PubMed1976

Fluorescent probe studies of haptoglobin type 2-1.

Haptoglobin is an alpha2 serum protein that forms an irreversible complex with hemoglobin. The combination between these two macromolecules resembles the binding of an antigen to its antibody except that the complex remains soluble. This investigation was undertaken to determine the nature of the hydrophobic sites on haptoglobin type 2-1. The interaction of 1-anilinonphthalene-8-sulfonate (ANS) with haptoglobin type 2-1 is characterized by a flourescence intensity in solutions containing ANS and haptoglobin as the pH is decreased from 9 to 4. The dissociation constant for the ANS interaction with haptoglobin 2-1 is 5.8 x 10--5 M at pH 7.0, 5.2 X 10--5 M at pH 5.0 AND 30.3 X 10--5 M at pH 4.0. Fmax shows no change in the pH range 6-9 but does show an increase at pH 4.0 when compared to the neutral region.

Anilino Naphthalenesulfonates↗
PubMed1979

[Haptoglobin study of sheep during the development process].

The development of haptoglobin blood system was studied in the sheeps during intrauterine development and early postnatal period. The haptoglobin content was shown to decrease with the foetus age, two peaks of its reliable increase having been, however, noted -- on the 55th and 105th days of development. After the birth the haptoglobin concentration in blood is relatively low, increases gradually and attains by the 8th month of life that in adult animals. In the blood serum of 45--120 days old foetuses two phenotypes of fetal haptoglobin were found; the adult haptoglobin is present only beginning from the 1st month of life.

Animals↗
PubMed1979

Haptoglobin in the serum of thoroughbreds in training.

A method is described for the measurement of haptoglobin in equine serum using the peroxidase activity of the haemoglobin-haptoglobin complex. The problems of interference with Fe2+ and Fe3+ ions are described. Normal values for haptoglobin in 629 blood samples from thoroughbreds in training are presented showing a log normal distribution with a 5 per cent to 95 per cent range of 0.42 to 1.7 g/litre. There was no consistent alteration in haptoglobin concentration throughout the season in spite of a change in red cell size and total bilirubin concentration. It is concluded that the measurement of haptoglobin is useful in the detection of frank haemolytic states but is insufficiently sensitive to detect mild red cell destruction. The test, after further investigation, might be used as an adjunct to the current batch of blood tests employed to assess liver function.

Animals↗
PubMed1979

Evaluation of a nephelometric assay for haptoglobin and its clinical usefulness.

Serum haptoglobin has been advocated as an indicator of intravascular hemolysis. We have evaluated a nephelometric determination of serum haptoglobin. The assay is sensitive and exhibits within-run precision in the range of 2.5-7.4% coefficient of variation (CV) and between-run precision of 7.0% (CV). In addition, when haptoglobin values determined with the nephelometric assay were compared with hemoglobin-binding capacity determined by electrophoresis, the correlation coefficient was 0.968. The assay is essentially independent of phenotype and free of significant interference by hemolysis. The clinical correlation of haptoglobin values obtained for 100 selected patients with the nephelometric technique correlated well, if less than 250 mg/L, with the presence of hemolytic disease.

Anemia, Hemolytic↗
PubMed1976

[Hereditary polymorphism in the haptoglobin system of schizophrenic patients and healthy subjects].

Hereditary polymorphism of haptoglobin is studied by means of starch gel electrophoresis in schizophrenic patients (200 persons) and in healthy people (154 persons), in habitants of Minsk. It is concluded that Minsk inhabitants do not differ considerably from the rest European population in their frequencies of haptoglobin alleles. No reliable differences in the distribution of haptoglobin genotypes were found between patients and healthy persons. However, hereditary types of haptoglobins turned to be markers of the course and the prognosis of schizophrenia.

Gene Frequency↗