The present invention provides a method for inhibiting chondroitinase activity in a substrate by introducing a non-substrate glycosaminoglycan (GAG) to the substrate containing the chondroitinase. The non-substrate GAG is undegradable by chondroitinase. The GAG may be administered as a single dose or in multiple doses. The chondroitinase may be Chondroitinase B, Chondroitinase C, Chondroitinase AC, or Chondroitinase ABC. The substrate may be one or more of dermatan sulfate, hyaluronic acid, chondroitin sulfate, or derivatives thereof. The non-substrate GAG may be from naturally unbranched homo-polysaccharide, unnaturally branched GAG, or a hybrid GAG molecule fused of two or three GAG chains, being produced by chemical synthesis or enzymatic reaction. The non-substrate GAG may be heparin, heparan sulfate, and keratan sulfate. The non-substrate GAG may bind to the active residue of the chondroitinase when being introduced to the substrate such that the chondroitinase is no longer enzymatically active.本發明提供一種藉由向含有軟骨素酶之受質中引入非受質糖胺聚糖（glycosaminoglycan，GAG）來抑制該軟骨素酶在該受質中之活性的方法。該非受質GAG不可被軟骨素酶降解。該GAG可以單次劑量或多次劑量形式投與。該軟骨素酶可為軟骨素酶B、軟骨素酶C、軟骨素酶AC或軟骨素酶ABC。該受質可為硫酸皮膚素（dermatan sulfate）、玻尿酸（hyaluronic acid）、硫酸軟骨素（chondroitin sulfate）或其衍生物中之一或多者。該非受質GAG可以來自天然非支鏈同元多糖、非天然支鏈GAG或由兩個或三個GAG鏈融合之混合GAG分子，藉由化學合成或酶促反應產生。該非受質GAG可為肝素、硫酸乙醯肝素及硫酸角質素。該非受質GAG可以在被引入該受質中時結合於該軟骨素酶之活性殘基，使得該軟骨素酶不再具有酶活性。
