PMID- 22506496
OWN - NLM
STAT- MEDLINE
DCOM- 20130326
LR  - 20131121
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 116
IP  - 43
DP  - 2012 Nov 1
TI  - Experimental and theoretical studies on the binding of epigallocatechin gallate 
      to purified porcine gastric mucin.
PG  - 13010-6
LID - 10.1021/jp212059x [doi]
AB  - Binding of epigallocatechin gallate (EGCG) to highly purified short side-chain 
      porcine gastric mucin similar to human MUC6 type has been studied by 
      ultraviolet-visible absorption spectroscopy (UV-vis), ultrafiltration isothermal 
      titration microcalorimetry (ITC) and transmission electron microscopy (TEM). The 
      thermodynamic equilibrium of EGCG binding to mucin has been quantitatively 
      determined using ultrafiltration and high-performance liquid chromatography 
      (HPLC)-UV/vis. The relationship suggests multilayer binding rather than simple 
      Langmuir monolayer binding of EGCG. By combining the ultrafiltration and ITC 
      data, the thermodynamic parameters of EGCG binding to mucin have been obtained. 
      The binding constant for the first layer is about an order of magnitude higher 
      than that of the consecutive multilayers. Negative entropy indicates multilayer 
      of EGCG formed. Hydrogen bonding may be responsible for the multilayer formation. 
      Increasing temperature resulted in a decrease in the binding affinity, further 
      suggesting that hydrogen bonds dominated the interaction energy. A TEM micrograph 
      of the EGCG-mucin complex revealed a monodispersion of blobs similar to pure 
      mucin solution but with relatively bigger size (about twice). It is proposed that 
      the EGCG-mucin binding process occurs by single and/or cluster of EGCG molecules 
      driven to the surface of the two hydrophobic globules of mucin by hydrophobic 
      interaction followed by hydrogen bond interaction between EGCG and mucin. Further 
      adsorption of EGCG molecules onto bound EGCG molecules to form multilayers can 
      also occur. This fits well with the observations that EGCG-mucin interaction 
      followed a multilayer adsorption isotherm, the energy released is dominated by 
      hydrogen bonds, and no large aggregates were formed.
FAU - Zhao, Yanyan
AU  - Zhao Y
AD  - China Agricultural University, Qing-hua-dong-lu, Beijing, P R China.
FAU - Chen, Longjian
AU  - Chen L
FAU - Yakubov, Gleb
AU  - Yakubov G
FAU - Aminiafshar, Termeh
AU  - Aminiafshar T
FAU - Han, Lujia
AU  - Han L
FAU - Lian, Guoping
AU  - Lian G
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120423
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
RN  - 0 (Gastric Mucins)
RN  - 0 (Solutions)
RN  - 8R1V1STN48 (Catechin)
RN  - BQM438CTEL (epigallocatechin gallate)
SB  - IM
EIN - J Phys Chem B. 2012 Nov 1;116(43):13149
MH  - Animals
MH  - Catechin/*analogs & derivatives/metabolism
MH  - Gastric Mucins/*isolation & purification/*metabolism
MH  - Humans
MH  - Models, Molecular
MH  - Protein Binding
MH  - Solutions
MH  - *Swine
MH  - Thermodynamics
EDAT- 2012/04/18 06:00
MHDA- 2013/03/27 06:00
CRDT- 2012/04/18 06:00
PHST- 2012/04/18 06:00 [entrez]
PHST- 2012/04/18 06:00 [pubmed]
PHST- 2013/03/27 06:00 [medline]
AID - 10.1021/jp212059x [doi]
PST - ppublish
SO  - J Phys Chem B. 2012 Nov 1;116(43):13010-6. doi: 10.1021/jp212059x. Epub 2012 Apr 
      23.