Sequence-independent processing site of the C-terminal domain (CTD) influences maturation of the RgpB protease from Porphyromonas gingivalis.

The Gram-negative periodontal pathogen Porphyromonas gingivalis produces a family of outer membrane-anchored proteases, the gingipains, shown to play an essential role in virulence of the organism. The C-terminal domain (CTD) of gingipains and other secreted proteins is known to be the targeting signal for maturation and translocation of the protein through the outer membrane. The CTD is subsequently cleaved during the secretion process. Multiple alignment of various CTDs failed to define a consensus sequence at the putative CTD processing site. Using mutagenesis, we were able to show that cleavage at the site is not dependent on a specific residue and that recognition of the site is independent of local sequence. Interestingly, length of the junction between the CTD and adjacent Ig-like subdomain has a critical influence on post-translational glycan modification of the protein, whereby insertion of additional residues immediately N-terminal to the cleavage site results in failure of glycan modification and release of soluble protease into the culture medium. Various hypotheses are presented to explain these phenomena. Knowledge of the role CTDs play in maturation of gingipains has broader application for understanding maturation of CTD homologues expressed by bacteria of the Bacteriodetes phylum.

Association Between Dentin Matrix Protein 1 (rs10019009) Polymorphism and Ankylosing Spondylitis in a Chinese Han Population from Shandong Province.

BACKGROUND: Ankylosing spondylitis (AS) is the most common rheumatic condition that is slowly progressive and predominantly affects adolescents. Pathological bone formation associated with AS is an important cause of disability. The aim of the study was to investigate the possible involvement of the genes related to endochondral ossification and ectopia ossification in genetic susceptibility to AS in a Chinese Han population. METHODS: Sixty-eight single nucleotide polymorphisms (SNPs) from 13 genes were genotyped in discovery cohorts including 300 AS patients and 180 healthy controls. The rs10019009 in dentin matrix protein 1 (DMP1) gene shown as association with AS after multiple testing corrections in discovery cohorts was replicated in a validation independent cohort of 620 AS patients and 683 healthy controls. The rs10019009 was assessed with bioinformatics including phylogenetic context, F-SNP and FastSNP functional predictions, secondary structure prediction, and molecular modeling. We performed a functional analysis of rs10019009 via reverse transcription-polymerase chain reaction, alkaline phosphatase (ALP) activity in human osteosarcoma U 2 OS cells. RESULTS: Interestingly, the SNP rs10019009 was associated with AS in both the discovery cohort (P = 0.0012) and validation cohort (P = 0.0349), as well as overall (P = 0.0004) in genetic case-control association analysis. After a multivariate logistic regression analysis, the effect of this genetic variant was observed to be independent of linkage disequilibrium. Via bioinformatics analysis, it was found that the amino acid change of the rs10019009 led to changes of SNP function, secondary structure, tertiary conformation, and splice mode. Finally, functional analysis of rs10019009 in U 2 OS cells demonstrated that the risk T allele of the rs10019009 increased enzymatic activity of ALP, compared to that of the nonrisk allele (P = 0.0080). CONCLUSIONS: These results suggested that the DMP1 gene seems to be involved in genetic predisposition to AS, which may contribute to the ectopic mineralization or ossification in AS. In addition, DMP1 gene may be a promising intervention target for AS in the future.

[Effects of irrigation scheme on the grain glutenin macropolymer's size distribution and the grain quality of winter wheat with strong gluten].

Taking two winter wheat (Triticum aestivum L.) cultivars (Gaocheng 8901 and Jimai 20) with high quality strong gluten as test materials, a 2-year field experiment was conducted to study the grain glutenin macropolymer (GMP)'s content and size distribution, grain quality, and grain yield under effects of different irrigation schemes. The schemes included no irrigation in whole growth period (W0), irrigation once at jointing stage (W1), irrigation two times at wintering and jointing stages (W2), respectively, and irrigation three times at wintering, jointing, and filling stages (W3), respectively, with the irrigation amount in each time being 675 m3 x hm(-2). Among the test irrigation schemes, W2 had the best effects on the dough development time, dough stability time, loaf volume, grain yield, GMP content, weighted average surface area of particle D(3,2), weighted average volume of particle D(4,3), and volume percent and surface area percent of particle size >100 microm of the two cultivars. The dough development time, dough stability time, and loaf volume were negatively correlated with the volume percent of GMP particle size <10 microm and 10-100 microm, while positively correlated with the volume percent of GMP particle size >100 microm, D(3,2), and D(4,3). It was suggested that both water deficit and water excess had detrimental effects on the grain yield and grain quality, and irrigation level could affect the wheat grain quality through altering GMP particle size distribution.

Photoenhanced gene transfection by a star-shaped polymer consisting of a porphyrin core and poly(L-lysine) dendron arms.

A star-shaped polymer (PP-PLLD) consisting of a porphyrin (PP) core and poly(L-lysine) dendron arms (PLLD) is synthesized by the click reaction, and its ability to deliver pEGFP is investigated in this paper. It is found that PP-PLLD has a good buffer capacity and can form compact complexes with pEGFP. In vitro assay indicates that PP-PLLD shows photoenhanced gene transfection efficiency. PP-PLLD consisting of only third generation PLLD shows a higher transfected cell number than PEI under a Xe lamp at the N/P ratio of 20, and meanwhile shows a neglectable cytotoxicity to HeLa cells. Therefore, PP-PLLD with suited irradiation is a promising nontoxic and photoinducible effective gene delivery strategy, which should be encouraged in gene therapy.

[Clinical study of the effect of preventing dentine hypersensitiveness by using Fluor Protector and Green Or on the prepared vital pulp abutment teeth].

PURPOSE: To study and evaluate the effect preventing dentine hypersensitiveness by using Fluor Protector or Green Or on the prepared vital pulp abutment teeth of PFM bridges. METHODS: 118 cases, 246 prepared vital pulp abutment teeth, were randomly divided into three groups: Experimental Group A--treated with the Fluor Protector and temporary crown; Experimental Group B--treated with the Green Or and temporary crown, and Control Group--only using temporary crown. The results of desensitization in 3 groups were evaluated. F test was used for analysis (DSPV6.01). RESULTS: Significant differences were found between experimental Group A, B and the control group after 1 week (when cementing the PFM bridges); and also after 1 month (P<0.05). But no significant difference was found between experimental Group A and B (P>0.05). CONCLUSIONS: The effect of preventing dental hypersensitiveness by using Fluor Protector or Green Or on the prepared vital pulp abutment teeth of PFM bridges is ideal. It is easy to use and worth being widely applied.