Capturing of acidic macromolecules from biological samples using a temperature-responsive polymer modified with poly-l-lysine

Abstract

We synthesized a temperature-responsive polymer, N-(isopropylacrylamide)-methacrylic acid copolymer, to which poly-l-lysine was introduced. The synthesized polymer as well as the parent polymer showed reversible soluble-insoluble changes in response to temperature changes across the lower critical solution temperature at 32 degree C in an aqueous solution. We found that the polymer efficiently captured acidic bio-macromolecules such as RNA, glycosaminoglycans and mucin-type glycoproteins in biological samples, and the captured molecules were recovered using aqueous NaCl solutions at high concentration. The target acidic molecules thus obtained will be employed for further studies such as structural analysis after brief desalting procedure. The proposed method does not require any chromatographic separations, but only needs a small volume of an aqueous salt solution for releasing captured molecules. Overall procedures are quite easy and simple, and are completed at least within 1 h. We show a few examples for capturing RNA and glycosaminoglycans from cultured cells using the polymer.

Fast analysis of glycosaminoglycans by microchip electrophoresis with in situ fluorescent detection using ethidium bromide

“…In the previous paper, we reported that HA molecules having higher molecular masses than those derived from pig skin are preferable for complex formation with poly-l-lysine [27]. Low intensity of the HA peak derived from pig skin ( Fig.…”

Effect of Host–Guest Interactions on the Cloud Points of Neutral Thermosensitive Homopolymers: Poly(N-n-propylmethacrylamide) and Polymers with Similar Structures

“…Thermosensitive polymers can undergo significant property changes in a controlled fashion by a temperature stimulus. − Thermosensitive polymers have potential in a variety of applications, such as the stationary phase in chromatography, separation of biomacromolecules, surface modification, drug delivery, and drug release. − The application in a given area may require a thermosensitive polymer with a specific cloud point and, therefore, tuning the cloud point of the thermosensitive polymers is an important research subject. Random copolymerization with another hydrophilic or hydrophobic monomer is a common method used to tune the cloud point of a thermosensitive polymer.…”

Thermally responsive polymer as a sieving matrix of proteins in capillary gel electrophoresis

“…10 When a basic chain, poly-L-lysine, was introduced to the copolymer of IPAAm and methacrylic acid, it was able to capture and recover acidic bio-macromolecules such as RNA, glycosaminoglycans and glycoproteins. 11 As well as the separation of small molecules and the affinity capturing of proteins, temperature-responsive polymers have played an important role in DNA sequencing with capillary electrophoresis (CE). 12 Capillary gel electrophoresis (CGE) can be used to separate peptides or proteins according to their molecular weights or sizes.…”