Hydrolysis of low-molecular-weight oligosaccharides and oligosaccharide alditols by pig intestinal sucrase/isomaltase and glucosidase/maltase

2000 ◽  
Vol 326 (4) ◽  
pp. 264-276 ◽  
Author(s):  
Sabine Hertel ◽  
Fritz Heinz ◽  
Manfred Vogel
2018 ◽  
Vol 1 (4) ◽  
pp. e00057 ◽  
Author(s):  
A.A Chistov ◽  
A.V. Talanova ◽  
M.V. Melnikova ◽  
S.S. Kuznetsova ◽  
E.F. Kolesanova

Low molecular weight chromogenic thrombin peptide substrates, p-nitroanilides of short peptides protected at their N-terminal amino group, were prepared by solid-phase peptide synthesis on polystyrene-divinylbenzene polymer with trityl groups with preliminary attached p-phenylene diamine moiety. After the cleavage from the resin peptide p-aminoanilides were mildly oxidized to p-nitroanilides with the mixture of potassium sulfate and persulfate. Adsorption onto polymer support Bio-Beads SM-2 with further elution by acetonitrile allowed easy separating peptide p-nitroanilides from the oxidizer and obtaining the thrombin chromogenic substrate preparations with the target substance contents of not less than 95% and yields of 30-40%. Thrombin effectively catalyzed hydrolysis of the prepared substrates with KM and Vmax values of 29-134 mM and 0.03-1/16 mM/s, respectively.


2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.


1981 ◽  
Vol 27 (12) ◽  
pp. 1334-1340 ◽  
Author(s):  
S. N. Sinha ◽  
B. L. Ghosh ◽  
S. N. Ghose

The presence of a cellulase inhibitor in the wheat bran culture of a fungus is reported for the first time. The inhibitor has a low molecular weight and is relatively stable to heat. It is absent from wheat bran and is not produced in a chemically defined medium. Unlike cellulase inhibitors of plant origin, this inhibitor is not a polyphenol. It inhibits the hydrolysis of cotton to a greater degree than that of filter paper or carboxymethylcellulose. In addition to inhibiting Aspergillus terreus cellulase, it also inhibits a variety of commercial cellulases.


1979 ◽  
Vol 92 (1) ◽  
pp. 105-118 ◽  
Author(s):  
A. Haeberli ◽  
H. Engler ◽  
C. von Grünigen ◽  
H. Kohler ◽  
H. Studer

ABSTRACT in this paper additional information on low molecular weight, soluble, intrathyroidal iodocompounds with slow metabolic rate is provided. These compounds have previously been localized autoradiographically within the follicular cells. Radioiodide was administered to rats on a normal iodine intake (6–7 μg/day) for 80 days to approach isotopic equilibration of the intrathyroidal iodine with the dietary radioiodide. When the isotope was omitted from the diet the intrathyroidal radioiodine was released with an apparent half-life of approximately 12 days. When the individual soluble components carrying radioiodine were analyzed after separation on Sephadex G-200, different apparent half-lives were found, the half-life of thyroglobulin (Tgb) being roughly 10 days and that of the low molecular weight iodocomounds being in the order of 60 to 100 days or more. In addition to the soluble low molecular weight iodocompounds, the radioactivity in the particulate fraction increased by 100 % during the tracer washout when compared to Tgb and the total soluble fraction. The soluble slow turnover iodocompounds contained a higher percentage of carbohydrate and total iodine than Tgb, while the relative amounts of each sugar analyzed (hexoses, fucose, hexosamine and sialic acid) were close to those in Tgb. Sephadex G-25 chromatography of the low molecular weight iodocompounds obtained after Sephadex G-200 separation resulted in the separation of 4 peaks. Two peaks identified as iodopeptides could be further analyzed. The carbohydrate composition of these peptides was similar to that of 2 glycopeptides obtained after in vitro enzymatic hydrolysis of purified Tgb with pronase. Slow equilibration with radioiodine, long apparent intrathyroidal half-life and carbohydrate content similar to that of Tgb, taken together with previously published data on intracellular localization of soluble intrathyroidal iodocompounds, suggest that the low molecular weight iodocompounds are products of in vivo hydrolysis of engulfed Tgb droplets.


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