TY - JOUR
T1 - Conformational study reveals amino acid residues essential for hemagglutinating and anti-proliferative activities of Clematis montana lectin
AU - Lu, Bangmin
AU - Zhang, Bin
AU - Qi, Wei
AU - Zhu, Yanan
AU - Zhao, Yan
AU - Zhou, Nan
AU - Sun, Rong
AU - Bao, Jinku
AU - Wu, Chuanfang
PY - 2014/7/10
Y1 - 2014/7/10
N2 - Clematis montana lectin (CML), a novel mannose-binding lectin purified from C. montana Buch.-Ham stem (Ranunculaceae), has been proved to have hemagglutinating activity in rabbit erythrocytes and apoptosis-inducing activity in tumor cells. However, the biochemical properties of CML have not revealed and its structural information still needs to be elucidated. In this study, it was found that CML possessed quite good thermostability and alkaline resistance, and its hemagglutinating activity was bivalent metal cation dependent. In addition, hemagglutination test and fluorescence spectroscopy proved that GuHCl, urea, and sodium dodecyl sulfate could change the conformation of CML and further caused the loss of hemagglutination activity. Moreover, the changes of fluorescence spectrum indicated that the tryptophan (Trp) microenvironment conversion might be related to the conformation and bioactivities of CML. In addition, it was also found that Trp residues, arginine (Arg) residues, and sulfhydryl were important for the hemagglutinating activity of CML, but only Trp was proved to be crucial for the CML conformation. Furthermore, the Trp, Arg, and sulfhydryl-modified CML exhibited 97.17%, 76.99%, and 49.64% loss of its anti-proliferative activity, respectively, which was consistent with the alterations of its hemagglutinating activity. Given these findings, Trp residues on the surface of CML are essential for the active center to form substrate-accessible conformation and suitable environment for carbohydrate binding.
AB - Clematis montana lectin (CML), a novel mannose-binding lectin purified from C. montana Buch.-Ham stem (Ranunculaceae), has been proved to have hemagglutinating activity in rabbit erythrocytes and apoptosis-inducing activity in tumor cells. However, the biochemical properties of CML have not revealed and its structural information still needs to be elucidated. In this study, it was found that CML possessed quite good thermostability and alkaline resistance, and its hemagglutinating activity was bivalent metal cation dependent. In addition, hemagglutination test and fluorescence spectroscopy proved that GuHCl, urea, and sodium dodecyl sulfate could change the conformation of CML and further caused the loss of hemagglutination activity. Moreover, the changes of fluorescence spectrum indicated that the tryptophan (Trp) microenvironment conversion might be related to the conformation and bioactivities of CML. In addition, it was also found that Trp residues, arginine (Arg) residues, and sulfhydryl were important for the hemagglutinating activity of CML, but only Trp was proved to be crucial for the CML conformation. Furthermore, the Trp, Arg, and sulfhydryl-modified CML exhibited 97.17%, 76.99%, and 49.64% loss of its anti-proliferative activity, respectively, which was consistent with the alterations of its hemagglutinating activity. Given these findings, Trp residues on the surface of CML are essential for the active center to form substrate-accessible conformation and suitable environment for carbohydrate binding.
KW - anti-proliferative activity
KW - chemical modification
KW - clematis montana Buch.-Ham lectin
KW - fluorescence spectroscopy
KW - hemagglutinating activity
UR - http://www.scopus.com/inward/record.url?scp=84911449640&partnerID=8YFLogxK
U2 - 10.1093/abbs/gmu085
DO - 10.1093/abbs/gmu085
M3 - Article
C2 - 25239139
AN - SCOPUS:84911449640
SN - 1672-9145
VL - 46
SP - 923
EP - 934
JO - Acta Biochimica et Biophysica Sinica
JF - Acta Biochimica et Biophysica Sinica
IS - 11
ER -