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S P Daiger

Publications and source records attributed to S P Daiger.

82 records · Page 5Linked to original sources
PubMed1981

Human thyroxine-binding globulin (TBG): heterogeneity within individuals and among individuals demonstrated by isoelectric focusing.

Isoelectric focusing of human plasma samples labeled in vitro with [125I]-thyroxine reveals considerable biochemical and genetic variation in thyroxine-binding globulin. (1) In all individuals tested, at least three primary isoelectric bands are seen in the pH range of 4.2 to 4.5, with additional bands at lower pH ranges. Similar patterns are produced by plasma from nonhuman primates. These band differences appear to be the result of differences in sialic acid content. TBG produces a single electrophoretic band on standard polyacrylamide gel electrophoresis. (2) Genetically determined, X-linked differences in electrophoretic mobility of TBG are observed in several human populations. Female homozygotes or male hemizygotes for the TBG slow variant (TBG-S) produce band patterns shifted by 0.5 pH unit cathodal to the common pattern (TBG-C). Female heterozygotes produce patterns with six-plus bands, representing the simple sum of the common and slow types. This difference is not the result of differences in sialic acid content. The gene frequency of this variant is 10% in American Blacks. (3) In pregnant women additional anodal bands are observed, giving the impression of a "shift," by integral steps, in the pattern relative to the nonpregnant type. This shift is abolished by mild neuraminidase treatment.

Animals↗
PubMed1981

Detection of genetic variation with radioactive ligands. IV. X-linked, polymorphic genetic variation of thyroxin-binding globulin (TBG).

A genetically determined, polymorphic electrophoretic variant of thyroxin-binding alpha-globulin (TBG) is found in sera from populations of African and Oceania origin, although not in Caucasians nor Orientals. The TBG polymorphism is inherited in X-linked fashion, based on data from American blacks, and thus provides an X-chromosome marker with a relatively high gene frequency in this ethnic group (frequency of the slow allele, TBGs, is 11%). This slow variant should prove valuable in expanding the map of the X chromosome and in linkage studies. An additional family exhibiting X-linked TBG deficiency is also described.

Chromosome Mapping↗
PubMed1978

Detection of genetic variation with radioactive ligands. III. genetic polymorphism of transcobalamin II in human plasma.

We detected genetically determined, electrophoretic variants of vitamin B12 binding proteins, most probably transcobalamin II, in human plasma. Polymorphic variants were observed in all populations tested; the two most common alleles (of at least four detected to date) attain frequencies of greater than 40% in Caucasians and Orientals. The variants are autosomally inherited and are seen as doublets in homozygotes, and four-banded patterns, the sum of two dissimilar homozygote patterns, in heterozygotes. The technique used in this survey, polyacrylamide gel electrophoresis (PAGE) autoradiography of plasma and serum labeled in vitro with 57Co-vitamin B12 is particularly applicable to the study of trace proteins such as the transcobalamins (10(-9)M). Possible functional variation in the TC II allele products is described, and the selective significance of this worldwide polymorphism is considered.

Autoradiography↗
PubMed1977

Detection of genetic variation with radioactive ligands. II. Genetic variants of vitamin D-labeled group-specific component (Gc) proteins.

A novel technique for detecting electrophoretic and quantitative variants of group-specific component (Gc) proteins is described. The technique, in vitro labeling with radioactive vitamin D followed by polyacrylamide gel electrophoresis and autoradiography (PAGE autoradiography), permits sensitive, high resolution detection of Gc variants by virtue of a physiologically significant property: the ability of Gc to bind vitamin D and 25-hydroxyvitamin D. Using this procedure, anodal Gc variants, with mobility similar to Gc Aborigine and Gc Eskimo, were observed in Chinese, Japanese, African Pygmies, and American Blacks. The gene frequency of these variants ranges from 2.6% to 15%; they were not previously known to be polymorphic in these populations. In addition to qualitative variants, individual variation in Gc band density ratios is documented and discussed. These studies not only illustrate the utility of PAGE autoradiography in screening Gc, but also confirm that a major functional role of Gc in man and other animals is the transport of vitamin D and vitamin D metabolites.

Adult↗
PubMed1977

Detection of genetic variation with radioactive ligands. I. Electrophoretic screening of plasma proteins with a selected panel of compounds.

To detect new genetic variation in human plasma proteins, a panel of 63 radioactive substances were screened as potential radioligands using polyacrylamide gel electrophoresis (PAGE) and autoradiography. Vitamins, hormones, drugs, amino acids, purines, pyrimidines, sugars and lipids labeled with 14C or other radionuclides were among those substances tested. A majority bound to albumin and a smaller fraction to prealbumins and lipoproteins. Several vitamins and hormones bound to specific alpha and beta globulins. (1) Electrophoretic polymorphisms of vitamin D-binding protein (group-specific component), a vitamin B12-binding protein (transcobalamin II), and thyroxine-binding alpha-globulin are described elsewhere. (2) Testosterone-binding beta-globulin (TeBG) showed an electrophoretic polymorphism in Caucasians and a possible deficiency allele. (3) Transcortin showed an electrophoretic doublet in all persons tested but no electrophoretic variation. (4) A protein binding derivative of norepinephrine or epinephrine was identified as transferrin. (5) A nonpolymorphic protein running cathodal to albumin and binding a derivative of riboflavin was tentatively identified as a fraction of albumin with mobility altered as a result of interaction with the ligand.

Adult↗
PubMed1975

Group-specific component (Gc) proteins bind vitamin D and 25-hydroxyvitamin D.

Group-specific component (Gc) proteins are human plasma proteins for which a worldwide polymorphism exists. As yet no functional role has been assigned this protein. We show that the products of both Gc alleles, proteins Gc 1 and Gc 2 (distinguished electrophoretically), bind substantial quantities of vitamin D and 25-hydroxyvitamin D. Three lines of evidence are reported: (1) Polyacrylamide gel electrophoresis and autoradiography of serum labeled with (14-C)vitamin D3 revealed patterns of radioactive bands identical to those expected of the two Gc alleles. Population gene frequencies for these proteins binding vitamin D were in the range of those reported for Gc, and individuals of known Gc phenotype were found to have the corresponding vitamin-D-binding phenotype. (2) Immunoelectrophoresis and autoradiography of labeled serum reacted against antiserum to human Gc revealed labeling by (14-C)vitamin D3 of Gc-antibody precipitation ares. (3) (14-C)vitamin D3 or 25-hydroxy(3-H)vitamin D3 was found to coprecipitate specifically with Gc in serum incubated with Gc antiserum. Use of these techniques demonstrated further that plasma proteins that bind vitamin D and that are immunologically similar to human Gc are found in mouse, rat, cow, horse, dog, rhesus monkey, and chimpanzee. We propose that Gc and "vitamin-D-binding alpha-globulin" are in fact the same portein, and that the ability of Gc to bind vitamin D may be directly related to the action of selection on this locus. These techniques may also find application in the study of other plasms transport proteins.

Alleles↗