In-flow SAXS investigation of whey protein isolate hydrolyzed by bromelain

Jiecheng Li; Zhi Yang; Xiaoling Lin; Sinong Wu; Guantian Li; Na Li; Don Otter; Fan Zhu; Christian Hartinger; Harold Corke; Yacine Hemar

doi:10.1016/j.colsurfa.2021.127662

In-flow SAXS investigation of whey protein isolate hydrolyzed by bromelain

Jiecheng Li, Zhi Yang^*, Xiaoling Lin, Sinong Wu, Guantian Li, Na Li, Don Otter, Fan Zhu, Christian Hartinger, Harold Corke, Yacine Hemar

^*Corresponding author for this work

Biotechnology and Food Engineering

Research output: Contribution to journal › Article › peer-review

6 Scopus citations

Abstract

In-flow small angle X-ray scattering (SAXS) was used to probe in real-time (typically every second) the hydrolysis of whey protein isolate (WPI) by bromelain. The WPI concentration was 2.5%, the enzyme to substrate ratio was 1:10, and the enzymatic reaction was followed for 90 min at 50 °C and pH 7. SAXS showed that the average size of WPI molecules was about 20 Å and that even at the completion of the enzymatic reaction some intact molecules of similar size remained; these are likely bromelain molecules and trace amount of BSA. SAXS allowed us to monitor the hydrolysis course through the calculation of the power-law exponent (P) and the Guinier scale factor (G) using a theoretical unified model fitting. The fitting exercise also indicated that bromelain hydrolysis transforms the globular WPI molecules into Gaussian polypeptides. The hydrolysis of WPI, which was completed within 40 min of hydrolysis, was confirmed by the degree of hydrolysis and turbidity measurements and by SDS-PAGE, which showed that bromelain has a broad specificity. This study demonstrates that SAXS is a powerful method to monitor in situ and real-time protein hydrolysis and can offer insights into protein structural changes that occur.

Original language	English
Article number	127662
Journal	Colloids and Surfaces A: Physicochemical and Engineering Aspects
Volume	631
DOIs	https://doi.org/10.1016/j.colsurfa.2021.127662
State	Published - 20 Dec 2021

Keywords

Bromelain
Enzymatic hydrolysis
SAXS
Whey protein isolate

Access to Document

10.1016/j.colsurfa.2021.127662

Cite this

@article{756f665fd06d46baafa04b3ed4781ad3,

title = "In-flow SAXS investigation of whey protein isolate hydrolyzed by bromelain",

abstract = "In-flow small angle X-ray scattering (SAXS) was used to probe in real-time (typically every second) the hydrolysis of whey protein isolate (WPI) by bromelain. The WPI concentration was 2.5%, the enzyme to substrate ratio was 1:10, and the enzymatic reaction was followed for 90 min at 50 °C and pH 7. SAXS showed that the average size of WPI molecules was about 20 {\AA} and that even at the completion of the enzymatic reaction some intact molecules of similar size remained; these are likely bromelain molecules and trace amount of BSA. SAXS allowed us to monitor the hydrolysis course through the calculation of the power-law exponent (P) and the Guinier scale factor (G) using a theoretical unified model fitting. The fitting exercise also indicated that bromelain hydrolysis transforms the globular WPI molecules into Gaussian polypeptides. The hydrolysis of WPI, which was completed within 40 min of hydrolysis, was confirmed by the degree of hydrolysis and turbidity measurements and by SDS-PAGE, which showed that bromelain has a broad specificity. This study demonstrates that SAXS is a powerful method to monitor in situ and real-time protein hydrolysis and can offer insights into protein structural changes that occur.",

keywords = "Bromelain, Enzymatic hydrolysis, SAXS, Whey protein isolate",

author = "Jiecheng Li and Zhi Yang and Xiaoling Lin and Sinong Wu and Guantian Li and Na Li and Don Otter and Fan Zhu and Christian Hartinger and Harold Corke and Yacine Hemar",

note = "Publisher Copyright: {\textcopyright} 2021 Elsevier B.V.",

year = "2021",

month = dec,

day = "20",

doi = "10.1016/j.colsurfa.2021.127662",

language = "英语",

volume = "631",

journal = "Colloids and Surfaces A: Physicochemical and Engineering Aspects",

issn = "0927-7757",

publisher = "Elsevier",

}

TY - JOUR

T1 - In-flow SAXS investigation of whey protein isolate hydrolyzed by bromelain

AU - Li, Jiecheng

AU - Yang, Zhi

AU - Lin, Xiaoling

AU - Wu, Sinong

AU - Li, Guantian

AU - Li, Na

AU - Otter, Don

AU - Zhu, Fan

AU - Hartinger, Christian

AU - Corke, Harold

AU - Hemar, Yacine

PY - 2021/12/20

Y1 - 2021/12/20

N2 - In-flow small angle X-ray scattering (SAXS) was used to probe in real-time (typically every second) the hydrolysis of whey protein isolate (WPI) by bromelain. The WPI concentration was 2.5%, the enzyme to substrate ratio was 1:10, and the enzymatic reaction was followed for 90 min at 50 °C and pH 7. SAXS showed that the average size of WPI molecules was about 20 Å and that even at the completion of the enzymatic reaction some intact molecules of similar size remained; these are likely bromelain molecules and trace amount of BSA. SAXS allowed us to monitor the hydrolysis course through the calculation of the power-law exponent (P) and the Guinier scale factor (G) using a theoretical unified model fitting. The fitting exercise also indicated that bromelain hydrolysis transforms the globular WPI molecules into Gaussian polypeptides. The hydrolysis of WPI, which was completed within 40 min of hydrolysis, was confirmed by the degree of hydrolysis and turbidity measurements and by SDS-PAGE, which showed that bromelain has a broad specificity. This study demonstrates that SAXS is a powerful method to monitor in situ and real-time protein hydrolysis and can offer insights into protein structural changes that occur.

AB - In-flow small angle X-ray scattering (SAXS) was used to probe in real-time (typically every second) the hydrolysis of whey protein isolate (WPI) by bromelain. The WPI concentration was 2.5%, the enzyme to substrate ratio was 1:10, and the enzymatic reaction was followed for 90 min at 50 °C and pH 7. SAXS showed that the average size of WPI molecules was about 20 Å and that even at the completion of the enzymatic reaction some intact molecules of similar size remained; these are likely bromelain molecules and trace amount of BSA. SAXS allowed us to monitor the hydrolysis course through the calculation of the power-law exponent (P) and the Guinier scale factor (G) using a theoretical unified model fitting. The fitting exercise also indicated that bromelain hydrolysis transforms the globular WPI molecules into Gaussian polypeptides. The hydrolysis of WPI, which was completed within 40 min of hydrolysis, was confirmed by the degree of hydrolysis and turbidity measurements and by SDS-PAGE, which showed that bromelain has a broad specificity. This study demonstrates that SAXS is a powerful method to monitor in situ and real-time protein hydrolysis and can offer insights into protein structural changes that occur.

KW - Bromelain

KW - Enzymatic hydrolysis

KW - SAXS

KW - Whey protein isolate

UR - http://www.scopus.com/inward/record.url?scp=85116561626&partnerID=8YFLogxK

U2 - 10.1016/j.colsurfa.2021.127662

DO - 10.1016/j.colsurfa.2021.127662

M3 - 文章

AN - SCOPUS:85116561626

SN - 0927-7757

VL - 631

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

M1 - 127662

ER -

In-flow SAXS investigation of whey protein isolate hydrolyzed by bromelain

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this