Studies on the Photolysis of L-Cysteine and L-Cystine

Studies on analogues of L-cysteine and L-cystine. III. The effect of selenium cystine on leukemia.

-CYSTEINE and related (omnpoumsds appear to have au importatit uole in the rnetabolismn of leukocytes. 6 A decrease its the availability of L-cyst-eine or L_cystimie* may therefore have important effects ots beukocyt-es. The Icukocytes of acute leukemia amid chromuic myeloid beukemia exhibit a niore rapid turmiover of radioactive L-cystiise thams do normnal leukocytes.7’ 8 Leukensic leukocytes ...

Studies on analogues of L-cysteine and L-cystine. I. Some structural requirements for inhibiting the incorporation of radioactive L-cystine by leukemic leukocytes.

Studies on analogues of L-cysteine and L-cystine. II. The effect of selenium cystine on Murphy lymphosarcoma tumor cells in the rat.

I HAS frequently beets suggested thatsulfhydryl comupounds may have an imuport-ant role imi cellular n etabo1ismn amid in cell growth and (livisiotu. Tints simlfhydryi (SH) comispoumids have I)een showis to stimumlate misitosis its a wide variety of cells amid tissues. Substances which oxidize SH comnpouticls (SI-I S-S) or coml)imie wit-h SH groimps to inactivate thetis have beets fouuid to inh...

Studies of l-Cysteine Biosynthetic Enzymes in Phaseolus vulgaris L.

In higher plants the biosynthesis of l-cysteine from l-serine, acetylCoA, and sulfide requires serine transacetylase and O-acetylserine sulfhydrylase. The distribution of these enzymes in kidney bean (Phaseolus vulgaris L. cv. Red Kidney) seedlings was determined. Between one-third and two-thirds of the serine transacetylase activity was associated with mitochondria, whereas all of the O-acetyl...

Org . On Cysteine and Cystine Peptides . Part V . l S - Trityl - and S - Diphenyl - methyl - cysteine and - cysteine Peptides

A new method for the preparation of S-trityl(i.e. triphenylmethyl) and S-diphenylmethyl-cysteines or -cysteine peptides involves treatment of cysteine or cysteine peptides with aralkylcarbinols in the presence of trifluoroacetic acid or hydrogen halides in acetic acid solution. The optimal conditions for the removal of these S-protecting aralkyl groups by trifluoroacetic acid or hydrogen halide...