Notation for serum-protein groups and the genes controlling their inheritance

Inheritance of a serum protein in swine

A study of polymorphism of the starch-gel electrophoretic pattern for one of the blood serum proteins in swine (tentatively designated protein B) reveils that it is controlled by a single palir of alleles exhibiting partial dominance. BB genotypes appear to have twice the amount of protein B that the Bb genotype has, while bb genotypes show no evidence of the protein. Present indications are that the Yorkshire and Landrace breeds differ in the frequiency of these genes.

IMMUNOLOGICAL AND BIOCHEMICAL STUDIES ON SERUM HAPTOGLOBIN

Antibody to purified type 1-1 human serum haptoglobin was obtained in rabbits. Using this antiserum it was demonstrated that the antigenic determinants of the haptoglobin molecule reside in both α- and β-chains. No immunological difference between the normal α^1F- and α^1S-chains of haptoglobin could be detected. A number of healthy individuals whose haptoglobin pattern appeared normal by starch gel electrophoresis were shown to possess a haptoglobin which could be distinguished immunologically from the common haptoglobin types. These immunological atypical haptoglobins have been observed in individuals of types 1-1, 2-1, and 2-2. Combined immunological and chemical studies of purified haptoglobin have enabled the construction of a tentative model for the structure of human type 1-1 haptoglobin.

Quantitative differentiation of the haptoglobin-related gene product from haptoglobin in human plasma: a possible test for tumor-associated antigen

The haptoglobin-related gene product (HGRP) having greater than 90% sequence homology with plasma haptoglobin, has recently been implicated as a tumor maker of recurrent breast cancer. Therefore, availability of a monoclonal antibody which is specific to the HGRP and ensuing ELISAs to quantitate the HGRP without cross-reactivity with plasma haptoglobin will allow determination of the clinical value of the HGRP in human plasma under various pathophysiological conditions. A peptide representing the first 34 residues of the N-terminal portion of the HRGP was synthesized and conjugated to keyhole limpet hemocyanin (KLH) to immunize Balb/c mice. Hybrid clones that produced specific antibodies to HRGP were screened with the same peptide but conjugated to bovine serum albumin (HRGP-BSA). From 12 hybridoma clones that recognized HGRP-peptide, we obtained one IgM producing clone (27.5) by limiting dilution technique that selectively reacted with HGRP-peptide with minimal cross-reactivity with haptoglobin. Using a separate monoclonal antibody, clone 21.7, which is directed to the alpha subunit of haptoglobin, we developed an enzyme-linked immunosorbent assay (ELISA) to determine the quantities of the HGRP in human plasma, which will allow assessment of HGRP as a clinical marker of malignancy.

Methods to quantitate human haptoglobin by complexation with hemoglobin

Native human haptoglobin isolated from normal human plasma by affinity chromatography on chicken hemoglobin -Sepharose was used as standard antigen. A direct sandwich ELISA for haptoglobin was developed, with human hemoglobin as a capturing agent. The peroxidase activity of the complex was measured as a means of detecting functional haptoglobin. The reactivities of monoclonal antibody vs. polyclonal antisera on the haptoglobin-hemoglobin complex were compared. Adopting a monoclonal antibody, clone 21.7, which is directed to the alpha chain of haptoglobin, a specific method to quantitate the native haptoglobin which can complex with hemoglobin has been developed.

Haptoglobin phenotyping of bloodstains by horizontal electrophoresis on a compact polyacrylamide gradient gel

A method is described for phenotyping haptoglobin by horizontal electrophoresis on a small polyacrylamide gradient gel. This method employs the same apparatus used in the separation of many red cell enzyme phenotypes and thereby eliminates the necessity for specialized vertical electrophoresis equipment.

An 11-kDa form of human immunodeficiency virus protease expressed in Escherichia coli is sufficient for enzymatic activity

In order to define the protease domain of human immunodeficiency virus 1, various regions of the pol open reading frame were cloned and expressed in Escherichia coli. Antiserum directed against the conserved retroviral protease active site was used to identify pol precursor and processed species containing the presumed protease domain. The smallest product that accumulates is about 11 kDa as measured by NaDodSO4/PAGE. This size agrees with that predicted from the presence in this region of two Phe-Pro sequences, which is one of the cleavage sites recognized by HIV protease. DNA encoding only the predicted 11-kDa protein was cloned, bypassing the need for autoprocessing, and the protein was expressed to a high level in E. coli. This form is active as demonstrated by its ability to specifically cleave protease-deficient pol protein in vivo in E. coli. Extracts of E. coli containing the 11-kDa protease also process human immunodeficiency virus gag substrates in vitro. These results demonstrate that the 11-kDa protease is sufficient for enzymatic activity and are consistent with a major role for this form in virus maturation.

Subtyping of haptoglobin--presentation of a new method

A method is described for large scale routine phenotyping of haptoglobin (Hp) which allows complete subtyping without prior purification of the Hp molecule. The procedure includes polyacrylamide gel isoelectric focusing of reduced, neuraminidase treated serum or plasma samples, and nitrocellulose blots developed with the immunoperoxidase technique. Different variables including sample treatment, electrofocusing, blotting procedures, and immunoperoxidase visualization are discussed. Characteristic alpha-chain patterns allow identification of the common allotypes 2FS, 2SS, 2FF, IS, IF, and Johnson. Isoelectric variations in the beta-chain may also be recognized. For comparison, two-dimensional Hp-patterns are presented. The results from concurrent typing of 600 samples by ordinary starch gel electrophoresis and by the described isofocusing technique, are evaluated.

Haptoglobin: an immunoregulatory role in tuberculosis?

A significant correlation was found between levels of haptoglobin in sera from Indonesian patients with tuberculosis and the extent to which these sera suppressed mitogen-driven activation of normal lymphocytes in vitro. As in a previous study we showed that there was an inverse relationship between haptoglobin levels and the circulating lymphocyte count in the same group of patients, it is now suggested that this protein has an immunoregulatory role in tuberculosis. Similar observations have been made by other workers on patients with cancer. There was no difference in the distribution of the 3 allotypes of haptoglobin in patients and healthy subjects nor was there any association between such allotypes and the lymphocyte count, the dermal reactivity to tuberculin or the degree of suppression.

Typing and subtyping of haptoglobin from native serum using disc gel electrophoresis in alkaline buffer: application to routine screening

A method with which the six common phenotypes of human haptoglobin can be identified using unseparated serum is described. In contrast to other reported methods, both typing and subtyping of haptoglobin can be performed by polyacrylamide gel electrophoresis in alkaline buffer using 0.1-4.0 microliter of native serum with hemoglobin added. Haptoglobin-hemoglobin complexes are visualized by their peroxidase activity using benzidine and barium peroxide. This relatively inexpensive and fast method seems particularly well suited for the typing and subtyping of haptoglobin from minute amounts in large series of sera and other body fluids and thus may be useful in medical genetics and forensic medicine.

Duplication within the haptoglobin Hp2 gene

DNA sequencing shows that the intragenic duplication within the human haptoglobin Hp2 allele was formed by a non-homologous, probably random, crossing-over within different introns of two Hp1 genes, probably in an Hp1F / Hp1S heterozygote.

Haptoglobin polymorphism in Egyptians

In 505 random serum samples from unrelated healthy genuine Egyptians, haptoglobin 2-2 phenotypes were most prevalent, though statistically were as common as haptoglobin 2-1 phenotypes. High inbreeding with average inbreeding coefficient of 0.0145 explains the deviation of Egyptian haptoglobin phenotypes from the Hardy-Weinberg equilibrium.

Association between immunoglobulin levels and known genetic markers in an Iraqi population

The effects of ABO compatibility mating, secretor, and haptoglobin subtypes on the levels of immunoglobulin have been determined in an Iraqi population. An interaction between the secretor and Lewis subtypes and levels of immunoglobulin was demonstrated. The IgG levels of the non-secretor group were lower than those of secretors. In contrast, haptoglobin subtypes displayed no significant effect on immunoglobulin levels. The interactions may indicate the indirect importance of these genetic markers in the evolution of resistance to infections.

Haptoglobin polymorphism and its relationship to malaria infections in The Gambia

The haptoglobin (Hp) status of the population of Keneba, The Gambia was investigated. Of the 825 persons examined 22.9% were ahaptoglobinaemic (HpO). The incidence of HpO was higher in the 209 persons showing malaria parasites in their blood (38.8%) than in non-parasitaemic individuals (17.5%). Children less than two years old had low incidences of HpO except in the first two months of life. After two years the incidence rose with little tendency to change in older age groups. No correlations were seen between HpO and sex, anaemia or sickle cell trait. However, a positive correlation was found with malariometric indices in all age groups except the two to four years. The Hp of individuals was found to be unstable suggesting that in Africans it is a poor genetic marker. These results indicate that Hp is utilized in removing free haemoglobin liberated intravascularly, during malaria infections and that although this is a major cause of the high incidence of HpO in The Gambia, other factors are also important.

Covalent structure of human haptoglobin: a serine protease homolog

The complete amino acid sequences and the disulfide arrangements of the two chains of human haptoglobin 1-1 were established. The alpha 1 and beta chains of haptoglobin contain 83 and 245 residues, respectively. Comparison of the primary structure of haptoglobin with that of the chymotrypsinogen family of serine proteases revealed a significant degree of chemical similarity. The probability was less than 10(-5) that the chemical similarity of the beta chain of haptoglobin to the proteases was due to chance. The amino acid sequence of the beta chain of haptoglobin is 29--33% identical to bovine trypsin, bovine chymotrypsin, porcine elastase, human thrombin, or human plasmin. Comparison of haptoglobin alpha 1 chain to activation peptide regions of the zymogens revealed an identity of 25% to the fifth "kringle" region of the activation peptide of plasminogen. The probability was less than 0.014 that this similarity was due to chance. These results strongly indicate haptoglobin to be a homolog of the chymotrypsinogen family of serine proteases. Alignment of the beta-chain sequence of haptoglobin to the serine proteases is remarkably consistent except for an insertion of 16 residues in the region corresponding to the methionyl loop of the serine proteases. The active-site residues typical of the serine proteases, histidine-57 and serine-195, are replaced in haptoglobin by lysine and alanine, respectively; however, aspartic acid-102 and the trypsin specificity, residue, aspartic acid-189, do occur in haptoglobin. Haptoglobin and the serine proteases represent a striking example of homologous proteins with different biological functions.

The normal cerebrospinal fluid proteins identified by means of thin-layer isoelectric focusing and crossed immunoelectrofocusing

The cerebrospinal fluid and serum proteins from 32 healthy individuals have been examined by isoelectric focusing in a pH-gradient from 3.5--11.0. Seventeen normal proteins have been identified by means of crossed immunoelectrofocusing. The pI-values of the main fractions of these proteins have been determined. On crossed immunoelectrofocusing microheterogeneity was observed for all of the proteins except haemopexin, gamma-trace protein of CSF and prealbumin of serum. Differences between serum and CSF were observed for 6 of the proteins. Prealbumin of CSF had a lower pI-value than in serum and showed partial immunological identity with prealbumin of serum. Transferrin of CSF included several components with lower sialic acid contents than in serum. The conversion of C'3-complement from beta-1-C to beta 1-A was slower in CSF than in serum. Qualitative differences between CSF and serum were also noticed for alpha2-macroglobulin and haptoglobin. IgM was not detected in CSF. In CSF the gamma-trace protein was found on isoelectric focusing in one third of the subjects. Two subjects had 2 close tau-fractions and another two had one unidentified band in the anodal IgG-area. The gamma-trace protein did not show any proteolytic activity, nor any resemblance in charge to 4 basic enzymes or with the histones tested.

Structure and evolution of artiodactyla haptoglobins

1. Artiodactyla haptoglobins (Hps), goat, sheep and cattle (family Bovidae), and pig (family Suidae) were structurally characterized. 2. The polymeric Hp systems of goat, sheep and cattle were similar to the polymeric human Hp system, while the monomeric system of pig was more comparable to the monomeric human form. 3. All members of the Artiodactyla (family Bovidae) examined exhibited a large polypeptide subunit, comparable to that of the beta subunit of human Hp. 4. In addition, a small subunit, similar in molecular weight to the human alpha 2 subunit, was demonstrated. Pig Hp was shown to have two subunits, one slightly larger than the human beta subunit and the other intermediate in size to the human alpha 1 and alpha 2 subunits. 5. Immunoelectrophoretic and immunodiffusion studies indicated complete cross reactivity among the polymeric Artiodactyla Hps. 6. The polymeric Hps do not, however, cross react with the monomeric pig Hp.

Haptoglobins in chronic lymphatic leukaemia

Haptoglobin phenotypes have been determined in 30 chronic lymphatic leukaemia patients and concentrations determined in 21 of these. The number of Hp1 phenotypes is slightly raised but not significantly so compared with a control population and is the same as that in first-degree relatives. Haptoglobin concentrations show higher concentrations in Hp1 than Hp2, as has previously been reported. It is concluded that haptoglobin genes contribute very little to any genetic influence on lymphatic leukaemia.

Evaluation of haptoglobin phenotype 0-0 in cirrhotic and non-cirrhotic hospital populations

The haptoglobin phenotypes of 3,332 individuals, consisting of 2,930 caucasians and 402 negroes living in the greater Boston area, were determined. Of these, 3,222 were hospitalized medical patients fully documented regarding diagnoses. One hundred and twentyeight of the total population studied were shown to exhibit starch gel anhaptoglobinaemia (3.7%). Re-evaluation on acrylamide gel of 118 0-0 samples revealed that the majority (94%) were derived from patients exhibiting hypohaptoglobinaemia rather than anhaptoglobinaemia.

Separation of the proteins of cerebrospinal fluid using gel electrofocusing followed by electrophoresis

The technique previously applied to serum can, with minor modifications, be applied to cerebrospinal fluid. Good protein patterns have been obtained and similarities as well as differences have been demonstrated between cerebrospinal fluid and serum. The patterns obtained should prove useful in neurological diagnosis.

Calorimetric studies of the haemoglobin-haptoglobin reaction

Haptoglobin binds haemoglobin so firmly that there is practically no dissociation. It would be expected that the heat of the reaction would be relatively large. The development of the microcalorimeter by Benzinger offered the opportunity to measure the heat of reaction. The experiments were carried out in the Beckman 190B Microcalorimeter in two ways: (1) a constant amount of haptoglobin (Kabi; 65mg.) with different amounts of haemoglobin, and (2) a constant amount of haemoglobin (32.5mg.) with different amounts of haptoglobin. The proteins, each in 5ml. of 0.15m-phosphate buffer, pH7.4, were placed in equal-volume calorimeter cells. The heat produced/mg. of haemoglobin was calculated from the slope of the curve for a constant amount of haptoglobin and from the maximum heat for a constant amount of haemoglobin. This heat is about 70kcal./mole at 37 degrees . DeltaH varies with temperature, being -70.2 at 37 degrees , -29.7 at 20 degrees and 7.2 at 4 degrees . From the amount of haptoglobin required to attain maximum heat with 32.5mg. of haemoglobin and the amount of haemoglobin required to attain maximum heat with 65mg. of haptoglobin, it appears that at excess of haptoglobin there is competition between the reactions of 2moles of haptoglobin with 1mole of haemoglobin (or 2 alphabeta-chains) and 1mole of haptoglobin with 1mole of haemoglobin.