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Effect of Amino Acid Residue and Oligosaccharide Chain Chemical Modifications on Spectral and Hemagglutinating Activity of Millettia dielsiana Harms.ex Diels.Lectin

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Acta Biochimica et Biophysica Sinica 2005年第1期37卷 47-54页

作者： Shun GAO Jie AN Chuan-Fang WU Ying GU Fang CHEN Yuan YU~1 Qia-Qing WU~* Jin-Ku BAO~* College of Life Sciences.Sichuan Uiversity,Chengdu 610064.China ~1Chengdu Institute of Biology.Chinese Academy of Sciences.Chengdu 610041.China CollegeofLifeSciences SichuanUniversityChengdu610064China

The effects of modifying the carbohydrate chain and amino acids on the conformation andactivity of Millettia dielsiana Harms.ex Diels.lectin（MDL）were studied by hemagglutination,fluorescenceand circular dichroism analysis.The modification of tryptophan residues led to a compete loss of hemagglu-tinating activity;however,the addition of mannose was able to prevent this loss of activity.The resultsindicate that two tryptophan residues are involved in the carbohydrate-binding site.Modifications of thecarboxyl group residues produced an 80% loss of activity,but the presence of mannose protected against themodification.The results suggest that the carboxyl groups of aspartic and glutamic acids are involved in thecarbohydrate-binding site of the lectin.However,oxidation of the carbohydrate chain and modification of thehistidine and arginine residues did not affect the Hemagglutinating Activity of MDL.Fluorescence studies ofMDL indicate that tryptophan residues are present in a relatively hydrophobic region,and the binding ofmannose to MDL could quench tryptophan fluorescence without any change in λmax.The circular dicbroismspectrum showed that all of these modifications affected the conformation of the MDL molecule to differentextents,except the modification of arginine residues.Fluorescence quenching showed that acrylamide andiodoacetic acids are able to quench 77% and 98% of the fluorescence of tryptophan in MDL,respectively.However,K1 produced a barely perceptible effect on the fluorescence of MDL,even when the concentrationof I- was 0.15 M.This demonstrates that most of tryptophan residues are located in relatively hydrophobicor negatively charged areas near the surface of the MDL molecule.

关键词： Millettia dielsiana Harms. ex Diels. lectin(MDL) chemical modification Hemagglutinating Activity circular dichroism fluorescence quenching

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Effects of Denaturation and Amino Acid Modification on Fluorescence Spectrum and Hemagglutinating Activity of Hericium erinaceum Lectin

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Acta Biochimica et Biophysica Sinica 2004年第5期36卷 343-350页

作者： Meng GONG, Jie AN, Hong-Zhou Lü, Chuan-Fang WU, Yi-Jin LI, Jing-Qiu CHENG, and Jin-Ku BAO*College of Life Sciences, Sichuan University, Chengdu 610064, China College of Life Sciences Sichuan University Chengdu 610064 China

A sialic acid-binding lectin (Hericium erinaceum lectin, HEL), isolated from fresh fruiting bodies of Hericium erinaceum, was treated with various temperature and pH to investigate its fluorescence spectra and Hemagglutinating Activity. It was found that the Hemagglutinating Activity of HEL was relatively steady below 60 °C and at pH from 6 to 11, and the change of Hemagglutinating Activity was relative to the change of hydrophobic areas where tryptophan residues located. In fluorescence quenching study of HEL by acrylamide and KI, it was indicated that nearly all the tryptophan residues of HEL located on the surface of the molecule, and most of them were in hydrophobic areas or negatively charged areas. Chemical modifica- tion of HEL proved that there were about twelve tryptophan residues in a HEL molecule and all of them were located on the surface or in the shallow groove of the molecule, and eight of them were essential for hemag- glutinating activity; aspartic acid or glutamic acid residues were involved in maintaining the crucial confor- mation of activity center and made great contribution to the Hemagglutinating Activity of HEL, but they could not touch the sialic acid molecule directly; tyrosine residues also played a role in the hemagglutinating activ- ity of HEL; while arginine, serine, threonine, histidine residues had no effect on the Hemagglutinating Activity of HEL.

关键词： sialic acid-binding lectin Hericium erinaceum lectin fluorescence spectrum and fluores- cence quenching Hemagglutinating Activity chemical modification

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In Vitro Evaluation of Gamma Irradiation on a Gel Formulation of Cratylia Mollis: Rheological Proporties and Microbiological Control

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Journal of Cosmetics, Dermatological Sciences and Applications 2012年第2期2卷 45-50页

作者： Maria Helena Madruga Lima-Ribeiro Ralph Santos-Oliveira Mauricelia Firmino De Santana Terezinha De Jesus Andreoli Pinto Irene Satiko Kikuchi Cheila Goncalves Mothe Luana Cassandra Breitenbach Barroso Coelho Maria Tereza Dos Santos Correia Ana Maria Dos Anjos Carneiro-Leao Laboratory of Immunopathology Keizo Asami(LIKA) Federal University of PernambucoRecifeBrazil Nuclear Engineering Institute Laboratory of NanoradiopharmaceuticalsRio de JaneiroBrazil Biochemistry Department Federal University of PernambucoRecifeBrazil Pharmacy Department University of Sao PauloSao PauloBrazil School of Chemistry Federal University of Rio de JaneiroRio de JaneiroBrazil Departament of Morphology and Animal Physiology Federal Rural University of PernambucoRecifeBrazil

Lectin Cramoll-1,4, obtained from Cratylia mollis seeds (beans camaratu) was structurally characterized, biologically and pharmacologically, but its use as a biopharmaceutical is not well documented. The objective of this study is to propose a biopharmaceutical formulation lectin Cramoll-1,4, test their hemagglutinating properties in vitro as well as the use of gamma radiation as a continuous process of decontamination formulation. It was made of the extraction and purification Cramoll-1,4, was developed a gel formulation using Carbopol? as a vehicle, at concentrations of 50, 100, 200, 300 and 600 μg was irradiated with 60Co gamma rays in a dose of 7.549 kGy·h–1. The proposed formulation at a concentration of 300 μg produced an increase in the hemagglutinating units Cramoll-1,4 due to the synergistic effect caused by gamma radiation. Considering the diverse use of lectins, specific molecular and structural factors, as well as changes resulting from its formulation, concentration, irradiation and route of administration is of utmost importance to continue the studies in vitro, for subsequent application in vivo to characterize the physiological and molecular processes involved in the response and cellular effects.

关键词： Gamma Radiation Natural Products Hemagglutinating Activity Cramoll-1 4

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