AggregateMonomerMw:2.5x108(expandedbelow)100-200M上手XHLLaggrecanMw:2.5x106-EpidermalgrowthMonomerfactor-likeHyaluronicdomainacido名名名名OO名名名名名O名0000O0名名OO名O-OOO量O量OOOOOOdComplementrepeatOOG2+名名名G300OO名名O名名名COo名名名名古名名名LinkooOOOOmodulesC-type lectin-G1likedomainLink+proteinGlcNAcGlcAOGalChondroitinKeratanGalNAcIdoAOMansulphatesulphateSer-Gly-xylose30/50100/100
Mw：2.5×106- 100/100 30/50 1009200 Mw：2.5×108- aggrecan Ser,Gly,xylose(
. Providing resilience incartilage is a consequenceof their highly hydrated state.Waterbinding is mediated by the sugars andlarge amount of sulphate residues· Resulting large volume occupied by anaggregate. It can only be reduced under pressure, byreleasing water· Aggregates are molecular shock absorbers orverystiffsponges· Releasing waterslowly under pressureandtaking it back up when pressure is released
• Providing-resilience-in-car7lage-is-a-consequenceof-their-highly-hydrated-state- • Water-binding-is-mediated-by-the-sugars-andlarge-amount-of-sulphate-residues- • Resul7ng-large-volume-occupied-by-anaggregate- • It-can-only-be-reduced-under-pressure,-byreleasing-water- • Aggregates-are-molecular-shock-absorbers-orvery-s7ff-sponges- • Releasing-water-slowly-under-pressure-andtaking-it-back-up-when-pressure-is-released-
Cartilage in various joints （关节）and invertebraldiscs（椎盘）effectivelycushions（缓冲）thejolts（震动）GAG-attachment regions becomelongerSegments of the aggrecan gene encoding thisportionareexpanded
Segments-of-the-aggrecan-gene-encoding-thispor7on-are-expanded Cartilage in various joints (关节) and in vertebral discs (椎盘) effectively cushions (缓 冲) the jolts (震动) ! GAG-attachment regions become longer!
o In fowls (鸡)oNaturallyoccurringnanomelia（短肢畸形mutation(突变) results in a truncatedaggrecan core protein lacking much of theGAG and C-terminal G3 globular domaino The mutant protein fails to support normallong-bone development, resulting in drasticskeletal（骨骼）abnormalities（异常）
o In-fowls-(鸡)- o Naturally-occurring-nanomelia-(短肢畸形)- muta7on-(突变)-results-in-a-truncatedaggrecan-core-protein-lacking-much-of-theGAG-and-C9terminal-G3-globular-domaino The-mutant-protein-fails-to-support-normallong9bone-development,-resul7ng-in-dras7cskeletal-(骨骼)-abnormali7es-(异常)-
o Proteoglycans found in extracellular matrices oftissueotherthancartilageo Core proteins of neurocan in brain and versican inblood vessels, skin, and other tissues closelyresembleaggrecanoDifferentGAGcanbeconjugatedo E.g. Perlican, a complex modular protein consistingof multiple copies of at least six different types ofglobulardomainand bearing just afewGAG chainso No details of selections of GAG providing physicaland organizational properties that suit therequirementofindividualtissues
o Proteoglycans-found-in-extracellular-matrices-of- 7ssue-other-than-car7lageo Core-proteins-of-neurocan in-brain-and-versican inblood-vessels,-skin,-and-other-7ssues-closelyresemble-aggrecan o Different-GAG-can-be-conjugatedo E.g.-Perlican,-a-complex-modular-protein-consis7ngof-mul7ple-copies-of-at-least-six-different-types-ofglobular-domain-and-bearing-just-a-few-GAG-chains- o No-details-of-selec7ons-of-GAG-providing-physicaland-organiza7onal-proper7es-that-suit-therequirement-of-individual-7ssues-