Proteolytic activity of two commercial proteinases from Aspergillus oryzae and Bacillus subtilis on ovine and bovine caseins

1991 ◽  
Vol 58 (4) ◽  
pp. 461-467 ◽  
Author(s):  
Rosina López-Fandiño ◽  
Mercedes Ramos ◽  
Estrella Fernández-García ◽  
Agustin Olano

SummaryElectrophoretic analysis of the action of two commercial enzymes, Neutrase 0·5 and MKC Fungal Protease, on whole casein and αs-, β- and κ-caseins from cows' and ewes' milk showed that Neutrase 0·5 chiefly degraded β-casein, giving rise to peptides soluble at pH 4·6 detectable by PAGE. In contrast, although MKC Fungal Protease caused intense hydrolysis of bovine β-casein, in ovine casein it resulted in more active degradation of αs- than β-casein. The latter enzyme did not produce peptides soluble at pH 4·6 detectable by PAGE. Both enzymes degraded κ-casein, yielding a breakdown product that exhibited an electrophoretic mobility similar to that of the breakdown product produced by the action of commercial rennet.

In a recent paper a new enzymic relation is recorded. For the enzymic hydrolysis of salicin—by the enzyme which Gabriel Bertrand and the author have named salicinase —it is found that, in an action of fixed duration, the temperature of greatest activity of the ferment is always the same, whatever the dilutions of substrate and of enzyme adopted for the determination. In other words, the duration of the action being constant, the optimum tem­perature of the ferment is independent of the concentration both of the substrate and of the enzyme. The observation is suggestive: if true of one enzyme it may be true of all, and possibly becomes the enunciation of a general law. Herein, for the moment, lies its main interest. In the present paper further experimental evidence for this hypothesis in given, in the case of another hydrolytic enzyme, the maltase of Aspergillus oryzæ (taka-diastase).


2006 ◽  
Vol 188 (21) ◽  
pp. 7609-7616 ◽  
Author(s):  
Alicia Monroe ◽  
Peter Setlow

ABSTRACT The Bacillus subtilis spore coat protein GerQ is necessary for the proper localization of CwlJ, an enzyme important in the hydrolysis of the peptidoglycan cortex during spore germination. GerQ is cross-linked into high-molecular-mass complexes in the spore coat late in sporulation, and this cross-linking is largely due to a transglutaminase. This enzyme forms an ε-(γ-glutamyl) lysine isopeptide bond between a lysine donor from one protein and a glutamine acceptor from another protein. In the current work, we have identified the residues in GerQ that are essential for transglutaminase-mediated cross-linking. We show that GerQ is a lysine donor and that any one of three lysine residues near the amino terminus of the protein (K2, K4, or K5) is necessary to form cross-links with binding partners in the spore coat. This leads to the conclusion that all Tgl-dependent GerQ cross-linking takes place via these three lysine residues. However, while the presence of any of these three lysine residues is essential for GerQ cross-linking, they are not essential for the function of GerQ in CwlJ localization.


1977 ◽  
Vol 166 (3) ◽  
pp. 411-413 ◽  
Author(s):  
G R J Burns ◽  
C H Wynn

1. The three arylsulphatases of Aspergillus oryzae exhibit pronounced kinetic differences and substrate specificities. Arylsulphatase I hydrolyses all substrates tested, whereas arylsulphatase III will not hydrolyse tyrosine O-sulphate or phenolphthalein disulphate. Arylsulphatase II does not hydrolyse p-nitrophenyl sulphate or phenolphthalein disulphate at appreciable rates in the absence of added phenolic compounds. Phenols such as tyramine increase the rate of hydrolysis of these substances by this enzyme 1000-fold. At pH 6.9 arylsulphatase I exhibits an apparent Km of 0.1 mM for p-nitrophenyl sulphate, whereas the Km of arylsulphatase III for this substrate is 1 mM. 2. These differences were utilized to develop an assay procedure which can be used to determine the separate activities of the three enzymes present in mixtures. This assay has potential use as a means of examining the relative activities of the three enzymes in investigations of the differences in the mechanisms regulating their synthesis.


2000 ◽  
Vol 90 (4) ◽  
pp. 422-425 ◽  
Author(s):  
Gota Kobayashi ◽  
Jinichi Toida ◽  
Takashi Akamatsu ◽  
Hiroki Yamamoto ◽  
Toshio Shida ◽  
...  

1959 ◽  
Vol 37 (1) ◽  
pp. 1361-1366 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers

Purified thrombin-C loses its clotting power upon acetylation. The thrombin-E which is produced during the acetylation has approximately twice the proteolytic activity as the original thrombin-C. Evidently amino groups are not necessary to have thrombin-E activity, but if o-acyl groups are also produced the enzyme does not hydrolyze p-toluenesulphonylarginine methyl ester (TAMe). The activity can be recovered by spontaneous hydrolysis of the o-acyl groups at pH 8.5. Thrombin-E does not activate fibrinogen, but does lyse fibrin. The optimum pH with TAMe as substrate is 8.8. It may be that thrombin-C is a dimer of the basic structure in thrombin-E.


Toxins ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 552 ◽  
Author(s):  
Liu ◽  
Chang ◽  
Wang ◽  
Yin ◽  
Huang ◽  
...  

In order to remove zearalenone (ZEA) detriment—Bacillus subtilis, Candida utilis, and cell-free extracts from Aspergillus oryzae were used to degrade ZEA in this study. The orthogonal experiment in vitro showed that the ZEA degradation rate was 92.27% (p < 0.05) under the conditions that Candida utilis, Bacillus subtilis SP1, and Bacillus subtilis SP2 were mixed together at 0.5%, 1.0%, and 1.0%. When cell-free extracts from Aspergillus oryzae were combined with the above probiotics at a ratio of 2:1 to make mycotoxin-biodegradation preparation (MBP), the ZEA degradation rate reached 95.15% (p < 0.05). In order to further investigate the MBP effect on relieving the negative impact of ZEA for pig production performance, 120 young pigs were randomly divided into 5 groups, with 3 replicates in each group and 8 pigs for each replicate. Group A was given the basal diet with 86.19 μg/kg ZEA; group B contained 300 μg/kg ZEA without MBP addition; and groups C, D, and E contained 300 μg/kg ZEA added with 0.05%, 0.10%, and 0.15% MBP, respectively. The results showed that MBP addition was able to keep gut microbiota stable. ZEA concentrations in jejunal contents in groups A and D were 89.47% and 80.07% lower than that in group B (p < 0.05), indicating that MBP was effective in ZEA biodegradation. In addition, MBP had no significant effect on pig growth, nutrient digestibility, and the relative mRNA abundance of estrogen receptor alpha (ERα) genes in ovaries and the uterus (p > 0.05).


2001 ◽  
Vol 183 (16) ◽  
pp. 4886-4893 ◽  
Author(s):  
Madan Paidhungat ◽  
Katerina Ragkousi ◽  
Peter Setlow

ABSTRACT Dormant Bacillus subtilis spores can be induced to germinate by nutrients, as well as by nonmetabolizable chemicals, such as a 1:1 chelate of Ca2+ and dipicolinic acid (DPA). Nutrients bind receptors in the spore, and this binding triggers events in the spore core, including DPA excretion and rehydration, and also activates hydrolysis of the surrounding cortex through mechanisms that are largely unknown. As Ca2+-DPA does not require receptors to induce spore germination, we asked if this process utilizes other proteins, such as the putative cortex-lytic enzymes SleB and CwlJ, that are involved in nutrient-induced germination. We found that Ca2+-DPA triggers germination by first activating CwlJ-dependent cortex hydrolysis; this mechanism is different from nutrient-induced germination where cortex hydrolysis is not required for the early germination events in the spore core. Nevertheless, since nutrients can induce release of the spore's DPA before cortex hydrolysis, we examined if the DPA excreted from the core acts as a signal to activate CwlJ in the cortex. Indeed, endogenous DPA is required for nutrient-induced CwlJ activation and this requirement was partially remedied by exogenous Ca2+-DPA. Our findings thus define a mechanism for Ca2+-DPA-induced germination and also provide the first definitive evidence for a signaling pathway that activates cortex hydrolysis in response to nutrients.


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