Two methods for the separation of human α-fetoprotein and albumin

Young, John L.; Webb, Brian A.

doi:10.1016/0003-2697(78)90464-5

Cited by 41 publications

(8 citation statements)

References 4 publications

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“…In that study, heterogeneity of human amniotic fluid and cord blood AFP was demonstrated by ampholyte displacement chromatography (Young and Webb, 1978). Furthermore, differences in the relative proportions of the AFP variants between AF and CB were noted (Young and Webb, 1978). How-ever, since the elution mechanism in ampholyte displacement chromatography is poorly understood and PIS are not obtained from this procedure it is impossible to compare these results with the present study.…”

Section: Discussionmentioning

confidence: 63%

“…To our knowledge, there has been only one other short report in the literature that attempted to characterize amniotic fluid AFP microheterogeneity. In that study, heterogeneity of human amniotic fluid and cord blood AFP was demonstrated by ampholyte displacement chromatography (Young and Webb, 1978). Furthermore, differences in the relative proportions of the AFP variants between AF and CB were noted (Young and Webb, 1978).…”

Section: Discussionmentioning

confidence: 84%

“…The appearance of the highly acidic form of human amniotic fluid AFP is interesting and has not been previously reported. However, it should be noted that previous studies examining human AFP charge microheterogeneity have used fetal serum and tissue extracts (Lester et al, ,1978aYoung and Webb, 1978;Parmelee et al, 1978;Alpert et al, 19731, or hepatoma serum and ascitic fluid (Purves et al, 1970;Alpert et al, 1972;Lester et al, 1976Lester et al, ,1978aAlpert et al, 1973) as the source of AFP. To our knowledge, there has been only one other short report in the literature that attempted to characterize amniotic fluid AFP microheterogeneity.…”

Section: Discussionmentioning

confidence: 99%

“…Comparison of the conA and chromatofocusing data strongly suggest that the biochemical basis for the observed charge microheterogeneity is not entirely related to the carbohydrate moieties of the glycoprotein. Others have shown that the charge microheterogeneity of AFP is not completely abolished by removal of the sialic acid residues (Lester et al, ,1978aYoung and Webb, 1978). Further studies have, however, shown that AFP avidly binds fatty acids (Hsia et al, 1980) and that fatty acid binding alters the PI of AFP (Parmelee et al, 1978).…”

Section: Discussionmentioning

confidence: 99%

“…Biochemically, AFP is a glycoprotein with a molecular weight of approximately 69,000 daltons and possessing about 4% carbohydrate (Morinaga et al, 1983). Like other glycoproteins, human AFP displays microheterogeneity, possessing both lectin (reviewed in Smith and Kelleher, 1980) and charge variants (Smith and Kelleher, 1980;Purves et al, 1970;Alpert et al, 1972Alpert et al, , 1973Lester et al, 1976Lester et al, , 1978ab; Young and Webb, 1978;Parmelee et al, 1978;). Interestingly, the lectin microheterogeneity of AFP appears to be tissue specific.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of human alpha fetoprotein charge microheterogeneity during fetal development

Keel¹,

Harms²,

Leal³

et al. 1990

Molecular Reproduction Devel

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Aliquotes of human amniotic fluid (AF), fetal serum (FS), and cord blood (CB) were obtained as by-products of routine clinical diagnostic procedures at term or in the second trimester of pregnancy. When samples of CB were applied to a pH 5.5-4 chromatofocusing gradient, three isoforms of AFP could be resolved; a pl 4.57 form (isoform IA, 52% AFP), a pl 4.27 form (isoform IB, 43% AFP), and one species that was bound to the column but could be eluted with 1.0 M NaCl (isoform II, pl less than 4.00, 5% AFP). Term AF displayed a profile similar to that observed in term CB. When samples of 15-20-week gestation AF were chromatofocused, the immunoreactive AFP recovered was distributed between isoform IA and IB (60%) and isoform II (40%). FS and AF obtained from same pregnancy (23-26 weeks) displayed an identical chromatofocusing profile. Aliquotes of AF subjected to conA revealed 83% reactive variants compared with greater than 95% reactive variants for CB. FS displayed a conA profile identical to CB. When individual CB charge isoforms were isolated and subjected to conA analysis, greater than 97% of the AFP bound to conA. In contrast, when AFP isoform IA and IB were isolated from midgestation AF, approximately 22% of the AFP did not bind to the lectin while 100% of isolated AFP isoform II eluted as the reactive variant. These data suggest that human AFP exists as at least three charge and two lectin variants and that the charge profile may change during fetal development.

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Section: Discussionmentioning

confidence: 63%

Section: Discussionmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Characterization of human alpha fetoprotein charge microheterogeneity during fetal development

Keel¹,

Harms²,

Leal³

et al. 1990

Molecular Reproduction Devel

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Sex differences in blood protein patterns: Two dimensional electrophoretic analysis of the acidic proteins of rat plasma

et al. 1982

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I 1Plasma from normal male and female rats was analyzed, after removal of albumin by affinity chromatography, by two-dimensional electrophoresis. The results demonstrated gender differences in two plasma proteins with apparent molecular weights of 70 000 and 84 000 and isoelectric points ranging from 6.2 to 6.4, and 5.1 to 5.5, respectively. Both proteins were found to be more concentrated in the plasma minus albumin (P-alb) fraction of females than males in both Wistar and Sprague-Dawley rats. The 70000 protein is serum albumin which was more completely removed from male plasma than female plasma. A possible mechanism responsible for this difference is discussed. The results support the existence of "maleness" and "femaleness" in blood protein patterns of rats.

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Electrophoretic and chromatographic differentiation of two forms of albumin in equilibrium at neutral pH: New screening techniques for determination of ligand binding to albumin

Bjerrum

Heegaard

1995

Electrophoresis

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Analysis of normal human serum by crossed hydrophobic interaction immunoelectrophoresis with Phenyl-Sepharose revealed a biphasic appearance of the albumin peak. The molecular mechanism behind this apparent albumin heterogeneity was investigated. Analysis of defatted purified albumin showed that a major fraction bound to the Phenyl-Sepharose and that addition of ligands (e.g. long-chain fatty acids, bilirubin, sulfonamides and warfarin) before electrophoresis blocked this binding to different degrees. A quantitative relation between ligand binding and the amount of nonbinding albumin was found. Thus the technique might be suitable for screening of ligand binding to albumin. Analysis of serum samples from newborns with hyperbilirubinemia revealed a positive correlation between the fraction of the nonretarded albumin and the bilirubin concentration. By chromatography on Phenyl-Sepharose, defatted albumin was separated into a binding and a nonbinding form and this technique was subsequently used to determine the kinetics of the intramolecular conversion. After rechromatography, each of the fractions could again be separated into two fractions, indicating the presence of an equilibrium. By varying the passage time for albumin on the column or varying the period between the first and the second separation it was possible to calculate the conversion rates. The half-life for the conversion was found to be as long as 1 1/4 h. It is the first time that a conformational change for albumin with such a long conversion time has been described experimentally.

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Two methods for the separation of human α-fetoprotein and albumin

Cited by 41 publications

References 4 publications

Characterization of human alpha fetoprotein charge microheterogeneity during fetal development

Characterization of human alpha fetoprotein charge microheterogeneity during fetal development

Sex differences in blood protein patterns: Two dimensional electrophoretic analysis of the acidic proteins of rat plasma

Electrophoretic and chromatographic differentiation of two forms of albumin in equilibrium at neutral pH: New screening techniques for determination of ligand binding to albumin

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