(508h) Calorimetric and Spectroscopic Studies on the Interaction between Angiotensin Converting Enzyme (ACE) Inhibiting Peptide GMKCAF and ACE

Calorimetric
and spectroscopic Studies on the interaction between Angiotensin Converting
Enzyme (ACE) inhibiting peptide GMKCAF and ACE

Xiongdiao Lan^1,2, Lixia Sun¹, Zefen Wang¹, Liqin
Zhou¹, Jianhua Sun¹, Zhangfa Tong¹,

Shuangfei Wang^2*, Dankui
Liao^1*

(1 School of Chemistry and
Chemical Engineering, Guangxi University, Nanning 530004, China; 2 Light
industry and Food Engineering College, Guangxi University, Nanning 530004,
China)

Abstract: Angiotensin
converting enzyme (ACE) inhibitory peptides exert antihypertensive effect by
inhibiting ACE activity. In this paper, the interaction between ACE inhibitory
peptide GMKCAF and ACE was studied by isothermal titration calorimetry, UV
absorption spectroscopy, fluorescence spectroscopy and circular dichroism. The
results demonstrated that GMKCAF was a non-competitive inhibitor, and the
binding of GMKCAF with ACE was a spontaneous exothermic process. Thermodynamic
parameters and the number of specific binding sites binding were changed
significantly with the increase of temperature. Spectroscopic studies indicated
that binding of GMKCAF led to the static fluorescent quenching of ACE together
with structural changes. This study is helpful to better understand the
inhibitory mechanism of ACE inhibitory peptides.

Keywords: Angiotensin
Converting Enzyme inhibitory peptides, binding, isothermal titration
calorimetry[1]