<mxfile host="app.diagrams.net"><diagram name="roadmap"><mxGraphModel dx="1422" dy="762" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="1600" pageHeight="900" math="0" shadow="0">
  <root>
    <mxCell id="0" />
    <mxCell id="1" parent="0" />
    <mxCell id="node1" value="核心问题：酸性木聚糖酶在毕赤酵母中高效分泌及低pH适应机制" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;fontStyle=1;verticalAlign=middle;align=center;" vertex="1" parent="1">
      <mxGeometry x="40" y="40" width="340" height="64" as="geometry" />
    </mxCell>
    <mxCell id="node2" value="策略：AOX1启动子驱动，比较3种信号肽（XynI自身、PHO1、α-MF）的分泌效率" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;fontSize=12;verticalAlign=middle;align=center;" vertex="1" parent="1">
      <mxGeometry x="40" y="162" width="340" height="64" as="geometry" />
    </mxCell>
    <mxCell id="node3" value="构建表达载体：三种信号肽分别融合xyn1基因，电转化毕赤酵母GS115" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;fontSize=12;verticalAlign=middle;align=center;" vertex="1" parent="1">
      <mxGeometry x="40" y="284" width="340" height="64" as="geometry" />
    </mxCell>
    <mxCell id="node4" value="分泌效率比较：XynI信号肽178 mg/L（38 U/ml）；α-MF 180 mg/L（38 U/ml）；PHO1 100 mg/L（15 U/ml）" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;fontSize=12;verticalAlign=middle;align=center;" vertex="1" parent="1">
      <mxGeometry x="40" y="406" width="340" height="64" as="geometry" />
    </mxCell>
    <mxCell id="node5" value="酶学性质：最适pH 2.5，最适温度40°C，比活213 U/mg（低于天然酶512 U/mg）" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#ffe6cc;strokeColor=#d79b00;fontSize=12;verticalAlign=middle;align=center;" vertex="1" parent="1">
      <mxGeometry x="40" y="528" width="340" height="64" as="geometry" />
    </mxCell>
    <mxCell id="node6" value="同源建模与定点突变：D73N活性降至19%，最适pH上移；E157Q最适pH移至3.5但保留全活性；E153T无影响；V141C/C150Y双突变无活性" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#e1d5e7;strokeColor=#9673a6;fontSize=12;verticalAlign=middle;align=left;" vertex="1" parent="1">
      <mxGeometry x="40" y="650" width="340" height="73" as="geometry" />
    </mxCell>
    <mxCell id="node7" value="结论：Asp-73和Glu-157位于活性位点裂缝上/下边缘，共同决定低pH最适性；XynI自身信号肽优于PHO1" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;fontStyle=1;verticalAlign=middle;align=center;" vertex="1" parent="1">
      <mxGeometry x="40" y="781" width="340" height="64" as="geometry" />
    </mxCell>
    <mxCell id="edge1" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;endArrow=block;endFill=1;strokeWidth=1.6;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;strokeColor=#6c8ebf;" edge="1" parent="1" source="node1" target="node2">
      <mxGeometry relative="1" as="geometry" />
    </mxCell>
    <mxCell id="edge2" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;endArrow=block;endFill=1;strokeWidth=1.6;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;strokeColor=#82b366;" edge="1" parent="1" source="node2" target="node3">
      <mxGeometry relative="1" as="geometry" />
    </mxCell>
    <mxCell id="edge3" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;endArrow=block;endFill=1;strokeWidth=1.6;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;strokeColor=#d6b656;" edge="1" parent="1" source="node3" target="node4">
      <mxGeometry relative="1" as="geometry" />
    </mxCell>
    <mxCell id="edge4" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;endArrow=block;endFill=1;strokeWidth=1.6;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;strokeColor=#b85450;" edge="1" parent="1" source="node4" target="node5">
      <mxGeometry relative="1" as="geometry" />
    </mxCell>
    <mxCell id="edge5" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;endArrow=block;endFill=1;strokeWidth=1.6;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;strokeColor=#d79b00;" edge="1" parent="1" source="node5" target="node6">
      <mxGeometry relative="1" as="geometry" />
    </mxCell>
    <mxCell id="edge6" style="edgeStyle=orthogonalEdgeStyle;rounded=1;orthogonalLoop=1;jettySize=auto;html=1;endArrow=block;endFill=1;strokeWidth=1.6;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;strokeColor=#9673a6;" edge="1" parent="1" source="node6" target="node7">
      <mxGeometry relative="1" as="geometry" />
    </mxCell>
  </root>
</mxGraphModel></diagram></mxfile>