Kinetics of hydrolysis of egg white protein by pepsin

Changqing, Ruan; Chi, Yujie; Zhang, Rui‐Dong

doi:10.17221/228/2009-cjfs

Cited by 40 publications

(31 citation statements)

References 27 publications

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“…It is suggested that high protein concentration became as a substrate in hibitor. The similar result was obtained by Ruan et al (2010) [16], it showed a decrease in DH at an increase in initial substrate concentration. According to Lescovac (2004) [17], the substrate concentration was the limiting factor.…”

Section: The Effect Of Initial Substrate Concentration On Degree Of Hsupporting

confidence: 86%

Hydrolysis of Nyamplung (Calophylluminophyllum) protein and their antioxidant activity

Yanti¹,

Hastuti²,

Sulistyo³

et al. 2016

AIP Conference Proceedings

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Abstract. The seedcake of nyamplung seeds still contains high protein. Recent studies show that protein hydrolysate has many useful effects, such as an antioxidant. The protein was isolated by the isoelectric precipitation method, further on hydrolysed into short chain peptides. The chemical composition of seedcake and the protein content of extract were analysed. The hydrolysis of the extract was carried out in a various condition such as substrate concentration, pH, and temperature for a different length of hydrolysis and the degree of hydrolysis was determine by TNBS method. The protein isolation process performed on the defatted seedcake produced 52.84 ± 0.07% of protein extract with a brownish colour. The degree of hydrolysis (DH) was increased by increasing the length of hydrolysis and showed the optimum DH with 6.15mg/mL substrate concentration. The increase of temperature also increased the DH, however at 70°C with 240 min time reaction, the DH tended to decrease. The pH of reaction between papain showed the similar DH among various pH of the reaction, with pH 7 showed the stable increasing DH till 240 min of reaction. The antioxidant activity showed an increase to 90% of inhibition by the addition of the hydrolysate to the system until 1300 ppm. However, the addition of more than 1300 ppm showed a reduction activity

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Section: The Effect Of Initial Substrate Concentration On Degree Of Hsupporting

confidence: 86%

Hydrolysis of Nyamplung (Calophylluminophyllum) protein and their antioxidant activity

Yanti¹,

Hastuti²,

Sulistyo³

et al. 2016

AIP Conference Proceedings

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“…A map dependent on the protein load complicates the comparison of deuteration levels for the protein in different states. This alteration suggests a level of substrate inhibition (21), and probably reflects a wide range of specificity constants (k cat /K m ) across the many individual cleavage sites presented in a protein substrate (22). Similar issues have been noted with trypsin (23).…”

mentioning

confidence: 53%

Nepenthesin from Monkey Cups for Hydrogen/Deuterium Exchange Mass Spectrometry

Rey

Yang

Burns

et al. 2013

Molecular & Cellular Proteomics

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Studies of protein dynamics, structure and interactions using hydrogen/deuterium exchange mass spectrometry (HDX-MS) have sharply increased over the past 5-10 years. The predominant technology requires fast digestion at pH 2-3 to retain deuterium label. Pepsin is used almost exclusively, but it provides relatively low efficiency under the constraints of the experiment, and a selectivity profile that renders poor coverage of intrinsically disordered regions. In this study we present nepenthesin-containing secretions of the pitcher plant Nepenthes, commonly called monkey cups, for use in HDX-MS. We show that nepenthesin is at least 1400-fold more efficient than pepsin under HDX-competent conditions, with a selectivity profile that mimics pepsin in part, but also includes efficient cleavage C-terminal to "forbidden" residues K, R, H, and P. High efficiency permits a solution-based analysis with no detectable autolysis, avoiding the complication of immobilized enzyme reactors. Relaxed selectivity promotes high coverage of disordered regions and the ability to "tune" the mass map for regions of interest. Nepenthesin-enriched secretions were applied to an analysis of protein complexes in the nonhomologous endjoining DNA repair pathway. The analysis of XRCC4 binding to the BRCT domains of Ligase IV points to secondary interactions between the disordered C-terminal tail of XRCC4 and remote regions of the BRCT domains, which could only be identified with a nepenthesin-based workflow. HDX data suggest that stalk-binding to XRCC4 primes a BRCT conformation in these remote regions to support tail interaction, an event which may be phosphoregulated. We conclude that nepenthesin is an effective alternative to pepsin for all HDX-MS applications, and especially for the analysis of structural transitions among intrinsically disordered proteins and their binding partners. Molecular & Cellular

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“…This equation modeled the degree of hydrolysis (h) as a function of the reaction time (t), which is the unique independent variable along with two kinetic constants (a, b) [12][13][14][15][16][17][18][19][20][21]. This model successfully described the typical shape of the protein hydrolysis time course and fit the experimental data with high accuracy, combining mechanistic foundation, simplicity and predictability.…”

Section: Introductionmentioning

confidence: 99%