Coupled reactions of immobilized enzymes and immobilized substrates: clinical application as exemplified by amylase assay.

1978 ◽  
Vol 24 (8) ◽  
pp. 1393-1398 ◽  
Author(s):  
R C Barabino ◽  
D N Gray ◽  
M H Keyes

Abstract We described a partitioned enzyme-sensor system, which incorporates an immoblized substrate and three or more discrete immobilized enzymes. This instrument measures alpha-amylase activity by passing the solution containing alpha-amylase over a column packed with immobilized starch. The resulting oligosaccharides are successively exposed to a column or columns containing immobolized glucose oxidase, catalase, glucoamylase or maltase, and glucose oxidase. The resulting hydrogen peroxide is detected by a three-electrode amperometric cell. All immobilized reagents were immobilized on a particulate, porous alumina to allow rapid and constant flow rate. With use of less than optimum immobilized reagents, alpha-amylase activity has been measured from about 5 to 200 kU/liter with a 50 microliter sample size. Lack of sensitivity is predominantly attributable to the low activity and low stability of immobilized maltase and glucoamylase. We believe that a clinical test using this system is feasible and desirable because the immobilized reagent system should allow for testing of alpha-amylase with excellent precision, convenience to the operator, and low cost.

1980 ◽  
Vol 26 (12) ◽  
pp. 1652-1655 ◽  
Author(s):  
W Hinsch ◽  
A Antonijewić ◽  
P V Sundaram

Abstract We describe routine methods for determining glucose in plasma with use of aldehyde dehydrogenase or glucose oxidase-aldehyde dehydrogenase immobilized in a nylon tube that is integrated into a continuous-flow system. Although the coupled-enzyme nylon-tube reactors require the presence of a third enzyme, catalase, in solution, the kinetics are not so complicated as to preclude reliable routine determination of glucose at very low cost. Precision is good, and results correlate well with those by the method involving glucose oxidase in solution. More than 3000 tests may be carried out with one reactor. The immobilized enzymes are stable for several months at 4 degrees C when not in use.


2015 ◽  
Vol 135 (2) ◽  
pp. AB4
Author(s):  
Andrea A. Pappalardo ◽  
Sherlyana Surja ◽  
Caitlin M. Campion ◽  
Sarah J. Aldrich ◽  
James N. Moy

2008 ◽  
Vol 32 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Renata Braga Souza Lima ◽  
José Francisco de Carvalho Gonçalves ◽  
Silvana Cristina Pando ◽  
Andréia Varmes Fernandes ◽  
André Luis Wendt dos Santos

This study aimed to characterize protein, oil, starch and soluble sugar mobilization as well as the activity of alpha-amylase during rosewood seed germination. Germination test was carried out at 25°C and the following parameters were analyzed: percentage of germination, initial, average, and final germination time. Seed reserve quantification was monitored in quiescent seeds and during different stages of radicle growth. Starch mobilization was studied in function of a-amylase activity. Germination reached 87.5% at the initial, average, and final time of 16, 21 and 30 days, respectively. Oil mobilization showed a negative linear behavior, decreasing 40% between the first and the last stage analyzed, whereas protein levels increased 34.7% during the initial period of germination. Starch content (46.4%) was the highest among those of the metabolites analyzed and starch mobilization occurred inversely to the observed for soluble sugars; alpha-amylase activity increased until the 15th day, a period before radicle emission and corresponding to the highest starch mobilization. The high percentage of rosewood seed germination may be related to the controlled condition used in the germination chamber as well as to high seed reserve mobilization, in special oil and starch.


2018 ◽  
Vol 14 (1) ◽  
Author(s):  
María Dolores Contreras-Aguilar ◽  
Damián Escribano ◽  
María Martín-Cuervo ◽  
Fernando Tecles ◽  
Jose Joaquín Cerón

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3633-3650
Author(s):  
Matheus Santin Padilha ◽  
◽  
Cileide Maria Medeiros Coelho ◽  
Natalia Carolina Moraes Ehrhardt-Brocardo ◽  
◽  
...  

Seeds with high vigor have greater capacity for hydrolysis and mobilization of stored reserves, which results in the formation of vigorous seedlings, and this behavior is observed under abiotic stress conditions. This study proposes to investigate the relationship of the enzyme alpha-amylase in lots of common-bean seeds with contrasting vigor, when subjected to the absence and presence of salt stress, aiming to identify the relationship of this enzyme with the vigor of the seed lot under these conditions. Seven common-bean cultivars were used. Physiological quality was determined by germination, vigor index and seedling length. The mobilization of reserves was evaluated under absence and presence of salt stress simulated with a NaCl solution with a concentration of 50 mmol L-1. The analyzed variables regarding reserve mobilization were reserve reduction, reserve reduction rate, seedling dry weight, reserve mobilization rate, starch, starch reduction rate and alpha-amylase activity. Results showed that the stress condition negatively affected all the evaluated variables; however, the cultivars classified as having greater vigor showed better physiological performance under stress. Salt stress in common-bean seeds affects seedling performance and reduces alpha-amylase activity during germination, and high-vigor seed lots exhibited higher enzyme activity in the no-stress condition.


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