相关实验视频

Updated: Jun 12, 2025

Rapid One-step Enzymatic Synthesis and All-aqueous Purification of Trehalose Analogues

Rapid One-step Enzymatic Synthesis and All-aqueous Purification of Trehalose Analogues

Published on: February 17, 2017

使用UV/VIS扩散反射率和固态NMR光谱学来确定含有酸盐,酸盐和胺缓冲剂的冷解三醇的固态酸度

Ashley Lay-Fortenbery¹, Xiaoda Yuan², Lukáš Veselý³

¹Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40526, USA.

Journal of pharmaceutical sciences

|September 23, 2024

概括

软化蛋白质配方可以在干燥过程中改变pH值. 固态NMR和UV-Vis光谱检测显示,酸盐缓冲区的pH值变化很小,但酸盐和胺缓冲区的变化很大,影响了蛋白质的稳定性.

科学领域:

制药科学制药科学
生物物理化学生物物理化学
分析化学分析化学

背景情况:

溶解蛋白质中的质子状态变化会影响稳定性和聚合性.
在冷凍化過程中的緩衝電離化轉移可以改變蛋白質微環境.
在固态配方中准确评估pH值对于药物开发至关重要.

研究的目的:

为了比较固态NMR (SSNMR) 和UV-Vis扩散反射光谱 (UVDRS) 用于测量溶解缓冲系统中的pH变化.
调查不同缓冲系统对冷化三糖配方表面pH值的影响.
评估电离探针的可靠性,以评估固态蛋白质配方中的pH值.

主要方法:

使用SSNMR光谱学与同位素标记的黄油酸探测碳酸酸电离.
采用UVDRS与紫色米作为pH指标染料.
通过两种方法在六种不同的含三醇的冷解缓冲系统中比较了从两种方法获得的表面pH值 (pHeq).

主要成果:

对于酸缓冲系统,SSNMR和UVDRS都显示出明显酸度的最小变化.
酸盐,酸盐和胺缓冲系统在溶解后的明显酸度表现出更大的变化.
虽然SSNMR和UVDRS之间的趋势相似,但数值pHeq值显示出差异,需要进一步调查潜在的原因.

结论:

SSNMR和UVDRS是评估冷化配方pH值变化的有价值工具.
缓冲区选择显著影响蛋白质在冷解过程中的pH稳定性.
SSNMR和UVDRS之间的差异凸显了固态系统中pH测量的复杂性以及需要仔细选择和解释探头的需要.

关键词:

扩散反射光谱学扩散反射光谱学软化液化化是什么意思固态NMR光谱学固态NMR光谱学固态酸性固态酸性固态酸性紫外线/VIS的使用情况.

更多相关视频

Determination of the Gas-phase Acidities of Oligopeptides

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

Mass Spectrometric Approaches to Study Protein Structure and Interactions in Lyophilized Powders

Mass Spectrometric Approaches to Study Protein Structure and Interactions in Lyophilized Powders

Published on: April 14, 2015

相关概念视频

IR and UV–Vis Spectroscopy of Carboxylic Acids

IR and UV–Vis Spectroscopy of Carboxylic Acids

In IR spectroscopy of carboxylic acids, the C=O bond shows a characteristic band between 1710 and 1760 cm⁻¹, and the O–H bond exhibits a broad band between 2500 and 3300 cm⁻¹.
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...

Chemical Shift: Internal References and Solvent Effects

Chemical Shift: Internal References and Solvent Effects

In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...

Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview

Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview

Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples.
The ATR process begins by directing a beam...

NMR and Mass Spectroscopy of Carboxylic Acids

NMR and Mass Spectroscopy of Carboxylic Acids

In ¹H NMR spectroscopy, acidic protons (–COOH) of carboxylic acids are highly deshielded and absorb far downfield, at around 9–12 ppm. The chemical shift value depends on the concentration and solvent used.
While α protons of carboxylic acids absorb at 2–2.5 ppm, β protons absorb further upfield.
Carboxylic acids are easily identified by dissolving them in deuterium oxide, which results in a rapid exchange of the acidic protons with deuterium. This leads to the...