Disease relevance of Biuret

• Improved biuret procedure for routine determination of urinary total proteins in clinical proteinuria [1].
• As compared to the biuret reaction, interferences from hemolysis have been about halved [2].
• Crude extracts from Escherichia coli expressing AtzD hydrolyzed cyanuric acid to biuret [3].
• The allophanate hydrolase from Pseudomonas sp. strain ADP, AtzF, was also shown to hydrolyze biuret slowly [4].
• The diagnostic accuracy for differentiating malignancy-related from non-malignant ascites was 93% for a alpha 1-protease inhibitor value > or = 50% of the pool plasma value and 90% for alpha 2-macroglobulin > or = 16%, C1-inhibitor > or = 40% (all functional assays), and total proteins > or = 20 g/l (biuret) [5].

High impact information on Biuret

• Urine specimens ultrafiltered through 3-kDa-cutoff membranes had substantial biuret reactivity, but absorbance maxima were consistent with cross-reactive amino acids rather than peptides [6].
• METHODS: We analyzed the specificity and kinetics of a biuret reaction for solutions of amino acids, organic compounds, peptides, proteins, and ultrafiltered urine specimens and compared the results with standard clinical assays for protein measurement [6].
• Protein in cerebrospinal fluid (CSF) was measured by a modified biuret procedure and in two automated instruments, the Du Pont aca and the Kodak Ektachem [7].
• To investigate the impact of this variability on clinical measurements of proteinuria, we collected urine specimens from patients with glomerular disease or drug-induced tubular nephrotoxicity and compared urinary protein concentrations as determined by the CBB method with those obtained by the biuret method [8].
• For the biuret assay, Lowry-Peterson assay, Bio-Rad Coomassie Blue assay, and Pierce BCA assay, the correlation coefficients were 0.96, 0.97, 0.89, 0.99, respectively [9].

Chemical compound and disease context of Biuret

• RESULTS: When excretion rates were determined by radioactivity it was apparent that only the albumin excretion rate increased significantly with STZ diabetes to a value of 354 +/- 166 microg/min which agrees with proteinuria determined by Biuret assay of 299.9 +/- 52.4 microg/min [10].

Biological context of Biuret

• Compound 4a when heated in base underwent hydrolysis of the hydantoin ring giving biuret N-(cyclohexylcarbamoyl)-N-(purin-6-ylcarbamoyl)glycine (5a) and N-(purin-6-ylcarbamoyl)glycine cyclohexylamide (6a) [11].
• Three plasma fibrinogen methods are presented based on (1) clottable protein assay by Biuret reagent, (2) measurement of clot absorbance and (3) thrombin time [12].
• In both cases the growth and yeast activity was followed by on line measurement of optical density, pH and pO2 at 30 degrees C. At the end of the bioprocess the concentration of protein in yeast biomass was determined off line by the biuret reaction [13].
• Simplate bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen (Biuret method), platelet count, platelet aggregation, serum functional antithrombin, and viscoelastic curves were measured on days one, three, six, and ten [14].

Anatomical context of Biuret

• Assay of cerebrospinal fluid protein: a rate biuret method evaluated [15].
• In a separate experiment, protein concentrations of turkey seminal plasma were estimated by biuret or Bradford methods [16].
• A rapid biuret assay for protein of whole fatty tissues [17].
• The total protein content of follicular fluid samples collected from both sources was similar and the results determined with the Biuret, Lowry and Biorad methods were also not significantly different (P>0.05) [18].
• A good correlation was obtained for total protein between the Chem-1 (y) and the biuret reference method (x) in 58 ascitic fluids (y = 1.02x -0.3; r = 1.00) [19].

Associations of Biuret with other chemical compounds

• The automated bromcresol green, manual immediate bromcresol green, cellulose acetate electrophoresis, 2-(4'-hydroxyazobenzene)benzoic acid binding, and Na2SO3 precipitation/biuret methods were evaluated [20].
• 1,6-Hexamethylene diisocyanate (HDI) is an aliphatic diisocyanate used in the manufacture of higher molecular weight biuret and trimer polyisocyanate resins [21].
• A comparison of the Biuret, Bradford, and bicinchoninic acid methods on the SDS-NaOH-extracted samples showed that the Biuret method was optimal, giving a value that was 90% of the reference value with a small variation (2.4% of the mean) [22].
• Daily and alternate-day supplementation of urea or biuret to ruminants consuming low-quality forage: III. Effects on ruminal fermentation characteristics in steers [23].
• The most popular method (sulphosalicylic acid turbidimetry) consistently performed the worst, and performance of the direct biuret procedure was also unacceptable; both methods should be discontinued [24].

Gene context of Biuret

• We compared various procedures and biuret reagents suggested for determination of protein in lipemic sera [25].
• Purification and characterization of TrzF: biuret hydrolysis by allophanate hydrolase supports growth [4].
• In vitro, TrzF was shown to hydrolyze biuret to liberate 3 mol of ammonia [4].
• In patients with a positive qualitative test (Combistix), quantitative measurement (Biuret) for proteinuria was carried out; when proteinuria was greater than 0.5 g/24 h, SDS gel electrophoresis was performed [26].
• The process has been characterized by methods including nonreduced SDS-PAGE, alpha 1 PI inhibition assay, and biuret protein assay [27].

Analytical, diagnostic and therapeutic context of Biuret

• Results by this method and a comparison method that included gel filtration and a modified biuret reaction correlated well (r = 0.951) [28].
• METHODS: Stimulated tear samples collected from 33 volunteers (17 men, 16 women), aged 23 to 51 years, who were fed or fasted for 12 hours, were assayed for total protein and insulin content by the biuret dye test and a radioimmunoassay, respectively [29].
• The separation and detection of biuret complexes of neuropeptides by capillary liquid chromatography with electrochemical detection was explored [30].
• The accuracy of the proposed procedure was assessed by comparisons with results obtained by using an ultrafiltration membrane that retains solutes with an average molecular weight in excess of 10 000 for separating of urinary proteins before they are measured with the biuret reaction [1].
• Optimization of the conditions for biuret complex formation for the determination of peptides by capillary electrophoresis with ultraviolet detection [31].

References