scholarly journals Enzyme Aggregation and Fragmentation Induced by Catalysis Relevant Species

2021 ◽  
Author(s):  
Kayla Gentile ◽  
Ashlesha Bhide ◽  
Joshua Kauffman ◽  
Subhadip Ghosh ◽  
Subhabrata Maiti ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Catalytic Activity ◽  
Glucose Oxidase ◽  
Inorganic Phosphate ◽  
Chemical Species ◽  
Low Ph ◽  
Native Structure ◽  
Native Form

It is usually assumed that enzymes retain their native structure during catalysis. However, the aggregation and fragmentation of proteins can be difficult to detect and sometimes conclusions are drawn based on the assumption that the protein is in its native form. We have examined three model enzymes, alkaline phosphatase (AkP), hexokinase (HK) and glucose oxidase (GOx). We find that these enzymes aggregate or fragment after addition of chemical species directly related to their catalysis. We used several independent techniques to study this behavior. Specifically, we found that glucose oxidase and hexokinase fragment in the presence of D-Glucose but not L-glucose, while hexokinase aggregates in the presence of Mg2+ ion and either ATP or ADP at low pH. Alkaline phosphatase aggregates in the presence of Zn2+ ion and inorganic phosphate. The aggregation of hexokinase and alkaline phosphatase does not appear to attenuate their catalytic activity. Our study indicates that specific multimeric structures of native enzymes may not be retained during catalysis and suggests pathways for different enzymes to associate or separate over the course of substrate turnover.

Some Methodological Modifications of the Technicon "SMA 12/60 AutoAnalyzer" System

1972 ◽  
Vol 18 (7) ◽  
pp. 630-642 ◽  
Author(s):  
Tevfik K Bigat ◽  
Abraham Saifer
Keyword(s):  
Alkaline Phosphatase ◽  
Glucose Oxidase ◽  
Aspartate Aminotransferase ◽  
Inorganic Phosphate ◽  
New Method ◽  
Green Method ◽  
Bromcresol Green ◽  
Made In

Abstract Methodological modifications have been made in our "SMA 12/60 AutoAnalyzer" system, to improve the reproducibility and accuracy of six commonly performed procedures. These include glucose with the glucose oxidase method, albumin with the bromcresol green method, and alkaline phosphatase with the sodium thymolphthalein monophosphate method. We have also modified the composition of the reagents used in the determination of protein, inorganic phosphate, and aspartate aminotransferase. A general approach that is useful for adapting a new method to a multichannel AutoAnalyzer system is discussed.

3-D structure of the D153G mutant of Escherichia coli alkaline phosphatase: an enzyme with weaker magnesium binding and increased catalytic activity

1995 ◽  
Vol 8 (9) ◽  
pp. 865-871 ◽  
Author(s):  
Chris G. Dealwis ◽  
Liqing Chen ◽  
Catherine Brennan ◽  
Wlodek Mandecki ◽  
Cele Abad-Zapatero
Keyword(s):  
Escherichia Coli ◽  
Alkaline Phosphatase ◽  
Catalytic Activity ◽  
Magnesium Binding

Haematological and serum chemistry profiles of ferrets (Mustela putorius furo)

1982 ◽  
Vol 16 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Elsbeth J. Lee ◽  
W. E. Moore ◽  
H. C. Fryer ◽  
H. C. Minocha
Keyword(s):  
Alkaline Phosphatase ◽  
Weight Gain ◽  
Total Protein ◽  
Alanine Aminotransferase ◽  
Inorganic Phosphate ◽  
Sorbitol Dehydrogenase ◽  
Serum Chemistry ◽  
Mustela Putorius ◽  
Mustela Putorius Furo

Female, male and castrated male ferrets were studied. Weight gain plateaued at 28-weeks of age with males about 500 g heavier than females. No statistically significant differences in haematology were observed with age, but alkaline phosphatase and alanine aminotransferase levels fell while glucose increased. Haemolysis led to various changes including marked increases in total protein, albumin, inorganic phosphate and sorbitol dehydrogenase.

Production and control of extracellular enzymes in Micrococcus sodonensis

1974 ◽  
Vol 20 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Cecily Mills ◽  
J. N. Campbell
Keyword(s):  
Alkaline Phosphatase ◽  
Inorganic Phosphate ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Synthetic Medium ◽  
Culture Conditions ◽  
The Other ◽  
Organic Nutrients ◽  
And Control ◽  
Logarithmic Growth

Micrococcus sodonensis has been shown to produce several extracellular enzymes: an alkaline phosphatase, at least two forms of phosphodiesterase, a 5′-nucleotidase, and an alkaline proteinase. The quantitative release of these enzymes into the culture medium during logarithmic growth under all the various culture conditions tested indicates that these enzymes are truly extracellular in nature. Inorganic phosphate repressed the production of the alkaline phosphatase in synthetic as well as in complex media, whereas, the repression of the production of active diesterase and 5′-nucleotidase by inorganic phosphate was partly reversed by the addition of supplemental organic nutrients to the culture medium. Proteinase production was independent of the culture conditions used. A mutant strain of M. sodonensis with an altered production of diesterase was obtained; the other extracellular enzymes were unaffected. These results suggest that the extracellular enzymes of M. sodonensis are not produced in a pleiotropic fashion since the level of one of the enzymes can be changed without affecting a corresponding change in the levels of the other enzymes. An extracellular high molecular weight carbohydrate fraction was shown to be produced by M. sodonensis in synthetic medium. The fraction was also shown to contain glycoprotein.

HORMONALLY INDUCED MODIFICATION OF HELA ALKALINE PHOSPHATASE WITH INCREASED CATALYTIC ACTIVITY

Isozymes ◽  
1975 ◽  
pp. 343-365 ◽  
Author(s):  
RODY P. COX ◽  
NIMAI K. GHOSH ◽  
KIRSTAN BAZZELL ◽  
MARTIN J. GRIFFIN
Keyword(s):  
Alkaline Phosphatase ◽  
Catalytic Activity

Renal responses of trout to chronic respiratory and metabolic acidoses and metabolic alkalosis

1999 ◽  
Vol 277 (2) ◽  
pp. R482-R492 ◽  
Author(s):  
Chris M. Wood ◽  
C. Louise Milligan ◽  
Patrick J. Walsh
Keyword(s):  
Amino Acids ◽  
Alanine Aminotransferase ◽  
Inorganic Phosphate ◽  
Metabolic Alkalosis ◽  
Titratable Acidity ◽  
Low Ph ◽  
Similar Increase ◽  
Urine Ph ◽  
Inorganic Phosphate Excretion ◽  
Renal Responses

Exposure to hyperoxia (500–600 torr) or low pH (4.5) for 72 h or NaHCO3 infusion for 48 h were used to create chronic respiratory (RA) or metabolic acidosis (MA) or metabolic alkalosis in freshwater rainbow trout. During alkalosis, urine pH increased, and [titratable acidity (TA) −[Formula: see text]] and net H+ excretion became negative (net base excretion) with unchanged [Formula: see text] efflux. During RA, urine pH did not change, but net H+ excretion increased as a result of a modest rise in [Formula: see text] and substantial elevation in [TA −[Formula: see text]] efflux accompanied by a large increase in inorganic phosphate excretion. However, during MA, urine pH fell, and net H+excretion was 3.3-fold greater than during RA, reflecting a similar increase in [TA −[Formula: see text]] and a smaller elevation in phosphate but a sevenfold greater increase in[Formula: see text] efflux. In urine samples of the same pH, [TA − [Formula: see text]] was greater during RA (reflecting phosphate secretion), and[Formula: see text] was greater during MA (reflecting renal ammoniagenesis). Renal activities of potential ammoniagenic enzymes (phosphate-dependent glutaminase, glutamate dehydrogenase, α-ketoglutarate dehydrogenase, alanine aminotransferase, phospho enolpyruvate carboxykinase) and plasma levels of cortisol, phosphate, ammonia, and most amino acids (including glutamine and alanine) increased during MA but not during RA, when only alanine aminotransferase increased. The differential responses to RA vs. MA parallel those in mammals; in fish they may be keyed to activation of phosphate secretion by RA and cortisol mobilization by MA.

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