1. L-histidine methyl ester dihydrochloride
V H Vilchiz, R E Norman, S C Chang Acta Crystallogr C. 1996 Mar 15;52 ( Pt 3):696-8. doi: 10.1107/s0108270195013308.
The title compound, C7H13N3O2(2+).2Cl-, has distances and angles quite similar to those of histidine hydrochloride monohydrate [Donohue & Caron (1964). Acta Cryst. 17, 1178-1180], except for the distances within the ester functionality.
2. BIOSYNTHESIS OF L-TYROSINE O-SULPHATE FROM THE METHYL AND ETHYL ESTERS OF L-TYROSINE
J G JONES, K S DODGSON Biochem J. 1965 Feb;94(2):331-6. doi: 10.1042/bj0940331.
1. Rat-liver supernatant preparations are capable of achieving the biological sulphation of l-tyrosine methyl ester, the reaction proceeding maximally at a substrate concentration of 30 mm and at pH 7.0. 2. Two sulphated products are formed, one of which has been identified as l-tyrosine O-sulphate. On the basis of indirect evidence the other product can be assumed to be l-tyrosine O-sulphate methyl ester. 3. An enzyme present in rat-liver supernatant preparations is capable of converting l-tyrosine O-sulphate methyl ester into l-tyrosine O-sulphate. This enzyme is inhibited by l-tyrosine methyl ester. 4. l-Tyrosine ethyl ester also yields two sulphated products when used as an acceptor in the liver sulphating system. One of these has been identified chromatographically as l-tyrosine O-sulphate and the other may be presumed to be l-tyrosine O-sulphate ethyl ester.
