DISRUPTION OF HYDROGEN-BONDING BETWEEN PLANT-CELL WALL POLYMERS BY PROTEINS THAT INDUCE WALL EXTENSION

被引:464
作者
MCQUEENMASON, S [1 ]
COSGROVE, DJ [1 ]
机构
[1] PENN STATE UNIV, DEPT BIOL, University Pk, PA 16802 USA
关键词
CELLULOSE; PAPER; PLANT CELL ENLARGEMENT;
D O I
10.1073/pnas.91.14.6574
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Plant cell enlargement is controlled by the ability of the constraining cell wall to expand. This ability has been postulated to be under the control of polysaccharide hydrolases or transferases that weaken or rearrange the load-bearing polymeric networks in the wall. We recently identified a family of wall proteins, called expansins, that catalyze the extension of isolated plant cell walls. Here we report that these proteins mechanically weaken pure cellulose paper in extension assays and stress relaxation assays, without detectable cellulase activity (exo- or endo- type). Because paper derives its mechanical strength from hydrogen bonding between cellulose microfibrils, we conclude that expansins can disrupt hydrogen bonding between cellulose fibers. This conclusion is further supported by experiments in which expansin-mediated wall extension (i) was increased by 2 M urea (which should weaken hydrogen bonding between wall polymers) and (ii) was decreased by replacement of water with deuterated water, which has a stronger hydrogen bond. The temperature sensitivity of expansin-mediated wall extension suggests that units of 3 or 4 hydrogen bonds are broken by the action of expansins. In the growing cell wall, expansin action is likely to catalyze slippage between cellulose microfibrils and the polysaccharide matrix, and thereby catalyze wall stress relaxation, followed by wall surface expansion and plant cell enlargement.
引用
收藏
页码:6574 / 6578
页数:5
相关论文
共 24 条
  • [1] BLOCK S M, 1987, American Biotechnology Laboratory, V5, P43
  • [2] STRUCTURAL MODELS OF PRIMARY-CELL WALLS IN FLOWERING PLANTS - CONSISTENCY OF MOLECULAR-STRUCTURE WITH THE PHYSICAL-PROPERTIES OF THE WALLS DURING GROWTH
    CARPITA, NC
    GIBEAUT, DM
    [J]. PLANT JOURNAL, 1993, 3 (01) : 1 - 30
  • [3] CASSAB GI, 1988, ANNU REV PLANT PHYS, V39, P321, DOI 10.1146/annurev.pp.39.060188.001541
  • [4] Clark J. A., 1985, PULP TECHNOLOGY TREA
  • [5] CHARACTERIZATION OF LONG-TERM EXTENSION OF ISOLATED CELL-WALLS FROM GROWING CUCUMBER HYPOCOTYLS
    COSGROVE, DJ
    [J]. PLANTA, 1989, 177 (01) : 121 - 130
  • [6] HOW DO PLANT-CELL WALLS EXTEND
    COSGROVE, DJ
    [J]. PLANT PHYSIOLOGY, 1993, 102 (01) : 1 - 6
  • [7] WALL EXTENSIBILITY - ITS NATURE, MEASUREMENT AND RELATIONSHIP TO PLANT-CELL GROWTH
    COSGROVE, DJ
    [J]. NEW PHYTOLOGIST, 1993, 124 (01) : 1 - 23
  • [8] NON-HYDROLYTIC DISRUPTION OF CELLULOSE FIBERS BY THE BINDING DOMAIN OF A BACTERIAL CELLULASE
    DIN, N
    GILKES, NR
    TEKANT, B
    MILLER, RC
    WARREN, AJ
    KILBURN, DG
    [J]. BIO-TECHNOLOGY, 1991, 9 (11): : 1096 - 1099
  • [9] Fry S. C., 1988, The growing plant cell wall: chemical and metabolic analysis.
  • [10] XYLOGLUCAN ENDOTRANSGLYCOSYLASE, A NEW WALL-LOOSENING ENZYME-ACTIVITY FROM PLANTS
    FRY, SC
    SMITH, RC
    RENWICK, KF
    MARTIN, DJ
    HODGE, SK
    MATTHEWS, KJ
    [J]. BIOCHEMICAL JOURNAL, 1992, 282 : 821 - 828