An Enzymatic Derivative Double Isotope Assay for l-Methionine
نویسندگان
چکیده
منابع مشابه
A Sensitive Double-Isotope Derivative Assay
A sensitive and specific double-isotope dilution method for assaying norepinephrine and epinephrine separately is described. The method is based on enzymatic conversion of these two catecholamines to their respective metanephrines and was applied successfully to measurement of resting plasma concentrations of norepinephrine and epinephrine in normal subjects with the finding that norepinephrine...
متن کاملDouble isotope derivative assay of aldosterone in biological extracts.
The selective measurement of aldosterone in biological fluids has been handicapped by the lack of specific and sensitive assays. Bioassay methods (l-4) have been limited by the variation inherent in animal response. Chemical methods (5-9) require extensive purification procedures to remove contaminants, and are therefore subject to variable recoveries of the steroid. Furthermore, the quantity o...
متن کاملA reverse double-isotope enzymatic histamine assay: advantages over single-isotope methods.
High concentrations of codeine necessary to demonstrate histamine release frog leukocytes interfere with histamine methylation, producing a concentration-dependent flattening of the histamine standard curves obtained from single-isotope (3H) assays . For this reason, the use of uniformly labeled l4C-histamine was investigated as as internal standard . This isotope serves as as internal standard...
متن کاملIsotope derivative analysis for proline, valine, methionine, and phenylalanine.
The development of the isotope derivative method of amino acid analysis and its application to the determination of aspartic and glutamic acids, serine, threonine, and hydroxyproline in protein hydrolysates has been described (1). In order to extend the method and to make possible the identification of the amino end-groups of proteins we have modified the procedure to include glycine and alanin...
متن کاملA sensitive double-isotope derivative assay for norepinephrine and epinephrine. Normal resting human plasma levels.
A sensitive and specific double-isotope dilution method for assaying norepinephrine and epinephrine separately is described. The method is based on enzymatic conversion of these two catecholamines to their respective metanephrines and was applied successfully to measurement of resting plasma concentrations of norepinephrine and epinephrine in normal subjects with the finding that norepinephrine...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1971
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)62034-4