Heterogeneity of human alpha-fetoprotein (HAFP) as revealed by agarose gel electrophoresis and isoelectric focusing in urea-acrylamide gels
HAFP was purified from five patients with hepatoma, one with gastric cancer, and one with an embryonal cell tumor, as well as from fetal liver and a monkey tumor cell line grown in tissue culture. The pattern of microheterogeneity of purified HAFP was defined for each HAFP isolate, and was demonstrated to be present in native sera, using crossed immunoelectrophoresis in agarose gels and isoelectric focusing in polyacrylamide gels containing 8 M urea. Three, and in one case four, species were seen in agarose, and were further resolved to reveal 6 major species with isoelectric focusing which could be correlated with the agarose gel variants. We have demonstrated a relationship between the immunosuppressive potency of certain HAFP preparations and the proportion of specific HAFP isomers which they contain as shown by these techniques. We have desialylated each of our preparations and demonstrated that this does not alter immunosuppressive potency but leaves residual complex microheterogeneity. Desialylated HAFP isolates contain six major HAFP isomers by isoelectric focusing, indicating that HAFP heterogeneity is based upon multiple charge differences in the HAFP molecule, apart from sialic acid content. The nature of these charge differences remain to be determined. We postulate that these charge differences modulate the immunosuppressive potency of HAFP.
- Research Organization:
- Franklin McLean Memorial Research Inst., Chicago, Ill. (USA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- EY-76-C-02-0069
- OSTI ID:
- 7291188
- Report Number(s):
- CONF-770860-1
- Resource Relation:
- Conference: 5. meeting of the international research group for carcino embryonic proteins, Copenhagen, Denmark, 6 Aug 1977
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
IMMUNOSUPPRESSION
NEOPLASMS
BIOCHEMISTRY
PROTEINS
PURIFICATION
ELECTROPHORESIS
GELS
HEPATOMAS
LIVER
PATIENTS
SIALIC ACID
BODY
CARBOHYDRATES
CHEMISTRY
COLLOIDS
DIGESTIVE SYSTEM
DISEASES
DISPERSIONS
GLANDS
ORGANIC COMPOUNDS
ORGANS
POLYSACCHARIDES
SACCHARIDES
550200* - Biochemistry