Free .ALPHA. subunits of glycoprotein hormone with dissimilar carbohydrates produced by pathologically different carcinomas.

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Abstract
The two kinds of glycoprotein hormone .alpha. subunit ectopically produced by an undifferentiated carcinoma of the left femoral region (TM-.alpha.) and an adenocarcinoma of the right external genitalia (FS-.alpha.) were examined for amino acid composition, isoelectric focusing, molecular weight, the ability to combine with standard hCG.beta. and affinity with lectins (Con A, Ricin and PNA). Both TM-.alpha. and FS-.alpha. exhibited immunoantigenicity similar to standard hCG.alpha.. Furthermore, there were no significant differences in the amino acid compositions of TM-.alpha., FS.alpha. or standard hCG.alpha.. In isoeletric focusing, while standard hCG.alpha. exhibited a neutral charge, both TM-.alpha. and FS-.alpha. exhibited strong negative charges. FS-.alpha. was as sensitive to sialidase as standard hCG.alpha., whereas most of the TM-.alpha. exhibited resistance to sialidase. TM-.alpha. contains sialidase-insensitive perpheral material with a negative charge. The affinity with Ricin-Sepharose indicated that most of the FS-.alpha. and some of the TM-.alpha. may contain terminal sialic acid and the penultimate structures. Gal.alpha.1.fwdarw. 4G1cNAc; the affinity with PNA-Sepharose indicated that both may also contain terminal sialic acid and the penultimate structure, Gal.alpha.1.fwdarw.3GalNAc. These observations suggest that dissimilar glycosylation processes are present in the carcinoma ectopic biosynthesis of glycoprotein hormone .alpha. subunit.

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