{"title":"探索α-淀粉酶辅助膜重塑的自下而上方法","authors":"Harshit Kumar , Sayar Mandal , Reena Yadav , Suhasi Gupta , Hemraj Meena , Mayur Kadu , Rajni Kudawla , Pratibha Sharma , Indu Pal Kaur , Subhabrata Maiti , John H. Ipsen , Tripta Bhatia","doi":"10.1016/j.chemphyslip.2023.105374","DOIUrl":null,"url":null,"abstract":"<div><p><span>Soluble alpha-amylases play an important role in the catabolism of polysaccharides. In this work, we show that the malt </span><em>α</em><span><span><span> -amylase can interact with the lipid membrane<span> and further alter its mechanical properties. Vesicle fluctuation spectroscopy is used for quantitative measurement<span> of the membrane bending rigidity of phosphatidylcholines </span></span></span>lipid vesicles from the shape fluctuation based on the whole contour of Giant </span>Unilamellar Vesicles<span> (GUVs). The bending rigidity of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid vesicles in water increases significantly with the presence of 0.14 micromolar alpha-amylase (AA) in the exterior solution. It appears that the enzyme<span> present in the external solution interacts with the outer layer of the bilayer membrane, leading to an asymmetry of the solution on either side of the bilayer membrane and altering its elasticity. At AA concentration of 1.5 micromolars and above, changes in the morphology of the GUV membrane are observed. The interaction between AA in the external solution and the external leaflet causes the bilayer membrane to curve spontaneously, leading to the formation of outbuds, giving a positive spontaneous curvature of </span></span></span><em>C</em><sub>0</sub> ≤ 0.05 <em>μ</em>m<sup>−1</sup><span> at ≈ 1 mg / ml of the AA concentration. We validate and characterize its concentration-dependent role in stabilizing the membrane curvature. Our findings indicate that the involvement of the enzyme, depending on the concentration, can have a considerable effect on the mechanical characteristics of the membrane.</span></p></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":null,"pages":null},"PeriodicalIF":3.4000,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Bottom-up approach to explore alpha-amylase assisted membrane remodelling\",\"authors\":\"Harshit Kumar , Sayar Mandal , Reena Yadav , Suhasi Gupta , Hemraj Meena , Mayur Kadu , Rajni Kudawla , Pratibha Sharma , Indu Pal Kaur , Subhabrata Maiti , John H. Ipsen , Tripta Bhatia\",\"doi\":\"10.1016/j.chemphyslip.2023.105374\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><span>Soluble alpha-amylases play an important role in the catabolism of polysaccharides. In this work, we show that the malt </span><em>α</em><span><span><span> -amylase can interact with the lipid membrane<span> and further alter its mechanical properties. Vesicle fluctuation spectroscopy is used for quantitative measurement<span> of the membrane bending rigidity of phosphatidylcholines </span></span></span>lipid vesicles from the shape fluctuation based on the whole contour of Giant </span>Unilamellar Vesicles<span> (GUVs). The bending rigidity of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid vesicles in water increases significantly with the presence of 0.14 micromolar alpha-amylase (AA) in the exterior solution. It appears that the enzyme<span> present in the external solution interacts with the outer layer of the bilayer membrane, leading to an asymmetry of the solution on either side of the bilayer membrane and altering its elasticity. At AA concentration of 1.5 micromolars and above, changes in the morphology of the GUV membrane are observed. The interaction between AA in the external solution and the external leaflet causes the bilayer membrane to curve spontaneously, leading to the formation of outbuds, giving a positive spontaneous curvature of </span></span></span><em>C</em><sub>0</sub> ≤ 0.05 <em>μ</em>m<sup>−1</sup><span> at ≈ 1 mg / ml of the AA concentration. We validate and characterize its concentration-dependent role in stabilizing the membrane curvature. Our findings indicate that the involvement of the enzyme, depending on the concentration, can have a considerable effect on the mechanical characteristics of the membrane.</span></p></div>\",\"PeriodicalId\":275,\"journal\":{\"name\":\"Chemistry and Physics of Lipids\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.4000,\"publicationDate\":\"2024-01-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemistry and Physics of Lipids\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0009308423000968\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"BIOCHEMISTRY & MOLECULAR BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemistry and Physics of Lipids","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009308423000968","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
摘要
可溶性α-淀粉酶在多糖的分解过程中发挥着重要作用。在这项工作中,我们发现麦芽α-淀粉酶能与脂膜相互作用,并进一步改变其机械特性。利用囊泡波动光谱法,基于巨型单拉米尔囊泡(GUVs)的整体轮廓,从形状波动中定量测量磷脂酰胆碱脂质囊泡的膜弯曲刚度。当外部溶液中含有 0.14 微摩尔的α-淀粉酶(AA)时,1-棕榈酰-2-油酰-sn-甘油-3-磷脂酰胆碱脂质囊泡在水中的弯曲刚度显著增加。看来外部溶液中的酶与双层膜的外层相互作用,导致双层膜两侧的溶液不对称,并改变了双层膜的弹性。当 AA 浓度达到或超过 1.5 微摩尔时,GUV 膜的形态会发生变化。外部溶液中的 AA 与外部小叶之间的相互作用导致双层膜自发弯曲,从而形成外芽,当 AA 浓度≈ 1 毫克/毫升时,外芽的自发曲率为 C0≤0.05 μm-1。我们验证并描述了它在稳定膜曲率方面的作用与浓度有关。我们的研究结果表明,根据浓度的不同,酶的参与会对膜的机械特性产生相当大的影响。
Bottom-up approach to explore alpha-amylase assisted membrane remodelling
Soluble alpha-amylases play an important role in the catabolism of polysaccharides. In this work, we show that the malt α -amylase can interact with the lipid membrane and further alter its mechanical properties. Vesicle fluctuation spectroscopy is used for quantitative measurement of the membrane bending rigidity of phosphatidylcholines lipid vesicles from the shape fluctuation based on the whole contour of Giant Unilamellar Vesicles (GUVs). The bending rigidity of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid vesicles in water increases significantly with the presence of 0.14 micromolar alpha-amylase (AA) in the exterior solution. It appears that the enzyme present in the external solution interacts with the outer layer of the bilayer membrane, leading to an asymmetry of the solution on either side of the bilayer membrane and altering its elasticity. At AA concentration of 1.5 micromolars and above, changes in the morphology of the GUV membrane are observed. The interaction between AA in the external solution and the external leaflet causes the bilayer membrane to curve spontaneously, leading to the formation of outbuds, giving a positive spontaneous curvature of C0 ≤ 0.05 μm−1 at ≈ 1 mg / ml of the AA concentration. We validate and characterize its concentration-dependent role in stabilizing the membrane curvature. Our findings indicate that the involvement of the enzyme, depending on the concentration, can have a considerable effect on the mechanical characteristics of the membrane.
期刊介绍:
Chemistry and Physics of Lipids publishes research papers and review articles on chemical and physical aspects of lipids with primary emphasis on the relationship of these properties to biological functions and to biomedical applications.
Accordingly, the journal covers: advances in synthetic and analytical lipid methodology; mass-spectrometry of lipids; chemical and physical characterisation of isolated structures; thermodynamics, phase behaviour, topology and dynamics of lipid assemblies; physicochemical studies into lipid-lipid and lipid-protein interactions in lipoproteins and in natural and model membranes; movement of lipids within, across and between membranes; intracellular lipid transfer; structure-function relationships and the nature of lipid-derived second messengers; chemical, physical and functional alterations of lipids induced by free radicals; enzymatic and non-enzymatic mechanisms of lipid peroxidation in cells, tissues, biofluids; oxidative lipidomics; and the role of lipids in the regulation of membrane-dependent biological processes.