Long, Z. | Search bioRxiv

bioRxiv2020

Computational Analysis of the Metal Selectivity of Metal Metalloproteinase 8

Matrix metalloproteinase (MMP) is a class of metalloenzyme that cleaves peptide bonds in extracellular matrices. Their functions are important in both health and disease of animals. Here using quantum mechanics simulations of the MMP8 protein, the coordination chemistry of different metal cofactors is examined. Comparisons found that Jhan-Teller effects in Cu(II) destabilize the wild-type MMP8 but a histidine to glutamine mutation at residue number 197 can potentially allow the MMP8 protein to utilize Cu(II) in reactions. Simulations also demonstrates the requirement of a conformational change in the ligand before enzymatic cleavage. The insights provided in here will assist future protein engineering efforts utilizing the MMP8 protein.Competing Interest StatementThe authors have declared no competing interest.View Full Text

biophysics↗

bioRxiv2020

Metabolomic markers of colorectal tumor with different clinicopathological features

BackgroundColorectal cancer (CRC) is the result of complex interactions between the tumors molecular profile and metabolites produced by its microenvironment. Despite recent studies identifying CRC molecular subtypes, a metabolic classification system is still lacking. We aimed to explore the distinct phenotypes and subtypes of CRC at the metabolic level. MethodsWe conducted an untargeted metabolomics analysis of 51 paired tumor tissues and adjacent mucosa using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. Multivariate analysis including principal component analysis, orthogonal partial least squares discriminant analysis and heat maps, univariate analysis, and pathway analysis were used to identify potential metabolic phenotypes of CRC. Unsupervised consensus clustering were used to identify robust metabolic subtypes, and evaluated their clinical relevance. ResultsA total of 173 metabolites (including nucleotides, carbohydrates, free fatty acids, and choline) were identified between CRC tumor tissue and adjacent mucosa. We found that lipid metabolism was closely related to the occurrence and progression of CRC and CRC tissues could be divided into three subtypes, and statistically significant correlations between different subtypes and clinical prognosis were observed. ConclusionsCRC tumor tissue exhibits distinct metabolic phenotypes. Metabolic differences between subtypes may provide a basis and direction for further clinical individualized treatment planning.

cancer biology↗