Structure and Forms

The structure of homocysteine is shown in Table 1 along with the related structures of cysteine and methionine. The most prominent features of homo-cysteine and cysteine are the free sulfhydryl groups located at the end of the side-chains of both amino acids. These sulfhydryl groups are highly susceptible to oxidation and the formation of disulfide linkages with other sulfhydryl compounds. The primary forms of homocysteine found in the blood (Table 1) consist of homocysteine in disulfide linkage with: (1) cysteine residues within the primary sequences of albumin and other plasma proteins (protein-bound); (2) free cysteines or cysteine-containing peptides (mixed disulfides); and (3) other homocysteine molecules (homocystine). Only about 1% of homocysteine in the blood is in the free-reduced form. Methionine, in contrast, does not have a free sulfhydryl group, and thus does not form disulfide compounds.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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