Reconstituted Fibril from Heterogenic Collagens-A New Method to Regulate Properties of Collagen Gels

Establishment of a targeted proteomics method for the quantification of collagen chain: Revealing the chain stoichiometry of heterotypic collagen fibrils in sea cucumber

Collagen is the most abundant and important structural biomacromolecule in sea cucumbers. The sea cucumber collagen fibrils were previously confirmed to be heterotypic, nevertheless, the stoichiometry of collagen α-chains governing the complexity of collagen fibrils is still poorly understood. Herein, four representative collagen α-chains in sea cucumber including two clade A fibrillar collagens, one clade B fibrillar collagen, and one fibril-associated collagen with interrupted triple helices were selected. After the screening of signature peptides and optimization of multiple reaction monitoring (MRM) acquisition parameters including fragmentation, collision energy, and ion transition, a feasible MRM-based method was established. Consequently, the stoichiometry of the four collagen chains was determined to be approximately 100:54:3:4 based on the method. The assembly forms of sea cucumber collagen fibrils were further hypothesized according to the chain stoichiometry. This study facilitated the quantification of collagen and understanding of the collagen constituents in sea cucumber.

Modification of natural pigskin collagen via cryogrinding: a focused study on its physiochemical properties

Natural pigskin was subjected to cryogrinding before extraction, and effects of the approach on extraction rate, structure, and properties of collagen were prospected systematically. It was found that the extraction rate multiplied gradually from 22% to 40% with an extended grinding duration from 0 to 20 min. Compared with natural collagen, the ground one soared by about 80% concerning the net yield. Electrophoresis revealed the stereo structures of the extracted collagen were not destroyed when ground, while a small amount of it degraded accordingly, whose conclusion was further corroborated by circular dichroism (CD) and infrared spectrometry. Results from contact angle (CA) test clarified that the hydrophilicity of collagen enhanced with prolonged grinding. Moreover, analysis of fibrillogenesis behavior verified that, after grinding, the assembly rate for collagen in the turbidity assay dented with a lengthened equilibrium time; finer fibril network with larger pore size and weakened elasticity was later observed. Methyl thiazolyl tetrazolium (MTT) analysis manifested that ground collagen was more conducive to cell proliferation. This polymer processing approach not only provides us with a facile approach to manipulate capacities of collagen but also sheds light on other potential substances beneath the same principle.

A quantum dot-based fluorescence sensing platform for the efficient and sensitive monitoring of collagen self-assembly

An efficient and sensitive assay for monitoring collagen self-assembly is presented.