ABSTRACT
Objective To study whether Nεcarboxymethyl lysine(CML)can form a good molecular docking with the scavenger receptor CD36and induce a stable interaction.Methods The interaction between CML and CD36was studied by co-immunoprecipitation.The binding mode and affinity of CD36to CML were tested using AutoDock 4.2,iBabel and XQuartz-2.7.7software respectively. Results Co-immunoprecipitation showed that anti-CD36antibody magnetic bead could precipitate CD36from the total protein in RAW264.7cells and anti-CML could detect CD36 binding CML.CD36had a good molecular docking with CML,CD36and CML interacted stably with each other.The affinity of CML to 4Q4Bprotein structure of CD4extracellular domain was -29.62kJ/mol.ARG82,ASN71and THR70were the products of amino acid receptor interaction. Further docking analysis showed that CML could form 3interacting hydrogen bonds with 4Q4B,and the docking prediction inhibition constant was 6.92with a root mean square deviation of 2.54.Conclusion A good molecular docking between CML and 4Q4Bprotein structure of CD36extracellular domain can induce a stable interaction between CML and CD36.Hydrogen bonding is the main interaction mode.
ABSTRACT
Objective@#To observe the correlation between Nε-carboxymethyl-Lysine (CML), the main component of advanced glycation end products and the calcification of the anterior tibial artery plaque in patients with diabetic foot post foot amputation.@*Methods@#Sixty patients hospitalized for foot amputation operation due to diabetic foot from June 2012 to June 2016 in the Department of Orthopedics, Affiliated Hospital of Jiangsu University were prospectively recruited.The patients were categorized into mild stenosis (0<stenosis<50%, n=20), moderate stenosis (50%≤stenosis<70%, n=20) and severe stenosis (70%≤stenosis≤100%, n=20) based on the color Doppler ultrasound assessed severity of anterior tibial artery stenosis.The baseline clinical data of patients were collected and anterior tibial artery was isolated.Then, HE staining, O-Cresolphthalein Complexone method, enzymic method and ELASA analysis were then performed to detect the evolution of calcification, arterial calcium content, alkaline phosphatase activity and serum CML concentration, respectively.@*Results@#The results from both color Doppler ultrasound scan before amputation and HE staining after amputation showed that echo intensity as well as spotty blue calcium particles of anterior tibial artery plaque increased significantly in proportion to degree of stenosis and destructed elastic plate of the arterial wall was evidenced in patients with severest stenosis.The content of calcium ((2.3±0.9), (3.9±1.3), (6.6±1.7) μmol/mg, respectively, P<0.001), ALP activity ((102.4±39.4), (202.3±73.4), (483.7±117.9) U/mg, respectively, P<0.001) and serum CML level ((28.9±4.4), (37.9±5.3), (57.3±7.1)μg/L, respectively, P<0.001) increased significantly in proportion to stenosis severity.Pearson correlation analysis showed that serum CML level was positively correlated with the content of calcium (r=0.749, P<0.001) and ALP activity (r=0.923, P<0.001), respectively.@*Conclusions@#Serum CML level is positively correlated with the calcification of anterior tibial arterial plaque in patients with diabetic foot and could be used to evaluate the calcification of anterior tibial arterial plaque and stenosis degree of anterior tibial arterial in these patients.