In order to alter the fluorescence properties of green fluorescent protein (GFP), aromatic non-natural amino acids were introduced into the Tyr66 position of GFP in a cell-free translation system using a four-base codon method. Two non-natural mutants (O-methyltyrosine and p-aminophenylalanine mutants) out of 18 mutants showed blue-shifted but weak fluorescence compared with wild-type GFP. Then...

This paper reports experiments on the stereospecificity observed in the monophenolase and diphenolase activities of mushroom tyrosinase. Several enantiomorphs of monophenols and o-diphenols were assayed: L-tyrosine, D,L-tyrosine, D-tyrosine; L-alpha-methyltyrosine, D,L-alpha-methyltyrosine; L-dopa, D,L-dopa, D-dopa; L-alpha-methyldopa, D,L-alpha-methyldopa; L-isoprenaline, D,L-isoprenaline and ...

In awake, unrestrained, intact rats, reserpine, para-chlorophenylalanine, 6-fluorotryptophan, and para-chloroamphetamine depleted whole brain serotonin and produced a substantial and sustained hyperventilation as evidenced by a 5--9 torr drop in PaCO2. Administration of 5-hydroxytryptophan to rats treated with para-chlorophenylalanine partially alleviated the hyperventilation. No change in vent...

OBJECTIVES It has been postulated that radiopharmaceuticals can be used to predict the therapeutic response to (chemo)therapy, which could lead to individualized treatment regimens. In this study, 18F-deoxyglucose, 99mTc-tetrofosmin, 125I-deoxyuridineribose, and 125I-methyltyrosine were tested for this purpose. METHODS The uterine sarcoma cell line MES-SA (MDR-) and its multidrug resistant va...

The effects of a variety of pharmacological and physiological manipulations on the activity of hepatic tyrosine transminase have been extensively investigated. Brain tyrosine transaminase, however, has received only limited attention. Since tyrosine transaminase may be important in the regulation of catecholamine biosynthesis in the brain, the effects of agents affecting catecholamine storage a...

Pheochromocytomas and paragangliomas are catecholamine-producing neoplasms that can cause life-threatening hemodynamic instability, particularly intraoperatively, when the tumor is manipulated. Preoperative medical management reduces both preoperative morbidity and mortality. The current review discusses the latest literature on preoperative management. Preoperative strategies include a nonsele...