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Superoxide anion radical (O 2 •− ) is a noxious reactive oxygen species (ROS). Transition metal ion complexes have been generally used as antioxidants to eliminate ROS. In this work, the soybean protein isolate (SPI), a biodegradable vegetable protein, was first combined with polyvinyl alcohol through hydrogen bonding for the synthesis of SPI-based polymer microgel (SPI-PmG) carrier. Furthermore, a kind of novel water-soluble biopolymer/metal complex conjugate (SCM@SPI-PmG) was prepared by binding the 4-hydroxy salicylaldehyde amino acid Schiff-base metal complexes (HOSalCysM, M = Cu, Zn) with the SPI-PmG. The structure, morphology and stability of SPI-PmG were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction pattern and thermogravimetric analysis. The result revealed that the diameter of the obtained SPI-PmG ranged from 150 to 400 nm. Besides, the scavenging superoxide anion free radical activity of biopolymer–metal complexes was determined by nitroblue tetrazolium light reduction assay method. Compared with the carrier SPI-PmG, the scavenging activity of the SCM@SPI-PmG was greatly improved. Remarkably, the superoxide dismutase (SOD) simulation of the SCCu@SPI-PmG reached 297.10%, and the SCZn@SPI-PmG simulation reached 35.13%. As a consequence, SCCu@SPI-PmG could be considered as a biofunctional mimic of enzyme SOD and has a promising application prospect in antioxidant drug field.

Superoxide anion radical (O $_{2}^{\bullet -}$ ) is a noxious reactive oxygen species (ROS). Transition metal ion complexes have been generally used as antioxidants to eliminate ROS. In this work, a neoteric water-soluble biopolymer metal complex (BSA-M) was prepared by conjugating the soluble biopolymer bovine serum albumin (BSA) with three transition metal ions (M, M =Cu, Co, Mn). The binding mode and ratio of metal ions bound to albumin were investigated. The BSA-M complexes were characterized by UV-Vis, circular dichroism (CD) spectra and polyacrylamide gel electrophoresis (PAGE). BSA served as polymer scaffold and the metal complex functioned as the catalytic active center. The results demonstrated that the structure of BSA remained unchanged when the binding ratio of transition metal ion complex to BSA was 5:1. Furthermore, the scavenging superoxide anion free radical (O $_{2}^{\bullet -}$ ) activity of biopolymer-metal complexes were determined by nitroblue tetrazolium light reduction assay method. The antioxidant capacity of BSA-M has markedly increased. The conjugated BSA-M (M=Cu, Mn) showed preeminent scavenging activity for O $_{2}^{\bullet -}$ , and the EC50 value of the BSA-Cu was 0.038 ±0.0013 μ mol⋅L −1, which is comparable to EC50 value (0.041±0.001 μ mol⋅L −1) of the natural superoxide dismutase (SOD), the analog quantity reached 107%. As a consequence, it can be considered as a bio-functional mimic of enzyme SOD and has a promising application prospect in antioxidant drug field.

More than a dozen single nucleotide polymorphisms (SNPs) have been associated with prostate cancer (PCa) risk from genome-wide association studies (GWAS). Their association with PCa aggressiveness and clinicopathologic variables is inconclusive.Twenty PCa risk SNPs implicated in GWAS and fine mapping studies were evaluated in 5,895 PCa cases treated by radical prostatectomy at Johns Hopkins Hospital, where each tumor was uniformly graded and staged using the same protocol.For 18 of the 20 SNPs examined, no statistically significant differences (P0.05) were observed in risk allele frequencies between patients with more aggressive (Gleason scoresor =4 + 3, or stageor =T3b, or N+) or less aggressive disease (Gleason scoresor =3 + 4, and stageor =T2, and N0). For the two SNPs that had significant differences between more and less aggressive disease rs2735839 in KLK3 (P = 8.4 x 10(-7)) and rs10993994 in MSMB (P = 0.046), the alleles that are associated with increased risk for PCa were more frequent in patients with less aggressive disease. Since these SNPs are known to be associated with PSA levels in men without PCa diagnoses, these latter associations may reflect the enrichment of low grade, low stage cases diagnosed by contemporary disease screening with PSA.The vast majority of PCa risk-associated SNPs are not associated with aggressiveness and clinicopathologic variables of PCa. Correspondingly, they have minimal utility in predicting the risk for developing more or less aggressive forms of PCa.