Effects of sucrose and mannitol on asparagine deamidation rates of model peptides in solution and in the solid state.
Effects of sucrose and mannitol on asparagine deamidation rates of model peptides in solution and in the solid state.
复制标题
蔗糖和甘露醇对溶液和固态模型肽的天冬酰胺脱酰胺率的影响。
DOI：
10.1002/jps.20372
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Borchardt,RonaldT
中科院分区：
文献类型：
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作者：
Li,Bei;O'Meara,MatthewH;Lubach,JosephW;Schowen,RichardL;Topp,ElizabethM;Munson,EricJ;Borchardt,RonaldT
在50°C下，在存在和不存在5%（w/v）蔗糖或甘露醇的pH 7缓冲溶液中，以及在50°C和30%相对湿度下，在从这些溶液冻干的固体样品中，研究了两种模型肽Gly-Gln-Asn-Gly-Gly（GQNGG）和Val-Tyr-Pro-Asn-Gly-Ala（VYPNGA）中的天冬酰胺（Asn）降解动力学。使用卡尔费休库仑滴定法、热重分析（TGA）、差示扫描量热法（DSC）、傅里叶变换红外光谱法（FTIR）和固态核磁共振（NMR）光谱法表征固体制剂。GQNGG和VYPNGA在不存在蔗糖和甘露醇的情况下在溶液中显示出相似的假一级脱酰胺速率。添加5%的蔗糖或甘露醇，降低率不超过17%。在蔗糖和甘露醇的固体制剂中，模型肽的降解速度比在这些碳水化合物的5%溶液中慢2- 80倍。模型肽的脱酰胺速率的比率取决于固体基质。在甘露醇固体中，GQNGG和VYPNGA的脱酰胺速率之比（GQNGG：VYPNGA）为1.8，而在蔗糖固体中，模型肽以相似的速率（GQNGG：VYPNGA 1.1）脱酰胺。DSC显示甘露醇制剂在冻干后立即基本上是无定形的，具有一些有序的晶体样结构;如FTIR和ssNMR所示，在储存期间有序结构的程度增加。相比之下，蔗糖制剂在冻干后基本上是无定形的，并且在储存期间保持这种状态。总之，结果表明，溶液中的5%蔗糖或甘露醇不显著改变模型肽的Asn脱酰胺速率，而蔗糖比固态的甘露醇更稳定模型肽以防止脱酰胺。
Asparagine (Asn) degradation kinetics in two model peptides, Gly-Gln-Asn-Gly-Gly (GQNGG) and Val-Tyr-Pro-Asn-Gly-Ala (VYPNGA), were studied at 50°C in pH 7 buffer solutions in the presence and absence of 5% (w/v) sucrose or mannitol and at 50°C and 30% relative humidity in solid samples lyophilized from these solutions. Solid formulations were characterized using Karl Fischer coulometric titration, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectrometry (FTIR), and solid-state nuclear magnetic resonance (NMR) spectroscopy. GQNGG and VYPNGA showed similar pseudo first-order deamidation rates in solution in the absence of sucrose and mannitol. Adding 5% sucrose or mannitol decreased the rates by no more than 17%. The model peptides degraded 2- to 80-fold more slowly in the solid formulations of sucrose and mannitol than in 5% solutions of these carbohydrates. Ratios of deamidation rates of the model peptides depended upon the solid matrix. In the mannitol solid, the ratio of deamidation rates of GQNGG and VYPNGA (GQNGG:VYPNGA) was ∼8, while in the sucrose solid, the model peptides deamidated at similar rates (GQNGG:VYPNGA ≅ 1). DSC showed the mannitol formulations to be largely amorphous immediately after lyophilization with some ordered, crystalline-like structure; the extent of ordered structure increased during storage as shown by FTIR and ssNMR. In contrast, the sucrose formulation was largely amorphous after lyophilization and remained so during storage. Together, the results showed that 5% sucrose or mannitol in solution does not significantly change the rates of Asn deamidation of the model peptides, while sucrose stabilizes the model peptides against deamidation more than mannitol in the solid state.