Abstract:
:Human salivary alpha-amylase participates in the initial digestion of starch and may be involved in the colonization of viridans streptococci in the mouth. To elucidate the role of histidine residues located near the starch-binding site on the streptococcal-binding activity, the wild type and three histidine mutants, H52A, H299A and H305A were constructed and expressed in a baculovirus system. While His52 is located near the non-reducing end of the starch-binding pocket (subsite S3/S4), the residues His299 and His305 are located near the subsites S1/S1'. For the wild type, the cDNA encoding the leader and secreted sequences of human salivary amylase was amplified by polymerase chain reaction from a human submandibular salivary-gland cDNA library, and subcloned into the baculovirus shuttle vector pVL1392 downstream of the polyhedrin promoter. Oligonucleotide-based, site-directed mutagenesis was used to generate the mutants expressed in the baculovirus system. Replacing His52 or His299 or His305 to Ala residue did not alter the bacterial-binding activity significantly, but these mutants did show differences in their catalytic activities. The mutant H52A showed negligible reduction in enzymatic activity compared to that of wild type for the hydrolysis of starch and oligosaccharides. In contrast, the H299A and H305A mutants showed a 12 to 13-fold reduction (90-92%) in starch-hydrolysing activity. In addition, the k(cat) for the hydrolysis of oligosaccharides by H299A decreased by as much as 11-fold for maltoheptaoside. This reduction was even higher (40-fold) for the hydrolysis of p-nitrophenyl maltoside, with a significant change in K(M). The mutant H305A, however, exhibited a reduction in k(cat) only, with no changes in the K(M) for the hydrolysis of oligosaccharides. The reduction in the k(cat) for the H305A mutant was almost 93% for maltoheptaoside hydrolysis. The pH activity profile for the H305A mutant was also significantly different from that of the wild type and the other two mutants. These results suggest that, although histidines at the starch-binding site of salivary amylase are involved in starch binding and catalysis, they may not participate in Streptococcus gordonii G9B binding.
journal_name
Arch Oral Bioljournal_title
Archives of oral biologyauthors
Tseng CC,Miyamoto M,Ramalingam K,Hemavathy KC,Levine MJ,Ramasubbu Ndoi
10.1016/s0003-9969(98)00112-5subject
Has Abstractpub_date
1999-02-01 00:00:00pages
119-27issue
2eissn
0003-9969issn
1879-1506pii
S0003996998001125journal_volume
44pub_type
杂志文章abstract:OBJECTIVE:to evaluate the association between XPD and XRCC3 polymorphisms and oral squamous cell carcinoma (OSCC). DESIGN:the sample consisted of 54 cases of OSCC and 40 cases of inflammatory fibrous hyperplasia (IFH). Genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism ...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2015.12.004
更新日期:2016-04-01 00:00:00
abstract::The fortuitous observation of salivary microliths in ferret was pursued in the present investigation. Major salivary glands obtained post-mortem from mature ferrets of either sex were examined with the use of histology and light microscopical histochemistry for calcium, protein, amino acids, mucosubstances and hydroly...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2005.07.009
更新日期:2006-03-01 00:00:00
abstract:OBJECTIVE:Hyposalivation is a common symptom of diabetes. Although microRNAs (miRNAs) play a role in the pathogenesis of diabetes, the specific effects of miRNAs on diabetic salivary glands are not clear. DESIGN:We used high-throughput technologies to screen differentially expressed (DE) miRNAs and mRNAs in submandibu...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2020.104947
更新日期:2020-12-01 00:00:00
abstract:OBJECTIVE:The aim of this study was to investigate the age-related changes in the articular disc, condyle, condylar fibrocartilage, and subchondral bone of the temporomandibular joint (TMJ) in rabbits. METHODS:Female New Zealand white rabbit aged 1, 4, 12, and 32 weeks were obtained. Each age group comprised 5 rabbits...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2019.104639
更新日期:2020-03-01 00:00:00
abstract:OBJECTIVE:Interspecies interactions of oral streptococci involve the production and excretion of antimicrobial compounds to compete successfully during colonization. Bacteriocin production by Streptococcus mutans and hydrogen peroxide (H2O2) production by Streptococcus sanguinis have been demonstrated as crucial for th...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2010.03.012
更新日期:2010-05-01 00:00:00
abstract:OBJECTIVE:To investigate the relationship between ATP and IL-6 in mechanical stress-induced REX-1 expression in SHEDs. METHODS:Cells were stimulated with mechanical stress (0-2.5 gcm(-2)), IL-6 (0.1-5 ng/ml), or ATP (10-100 μM) for 2h in serum-free media. IL-6 and REX-1 expression was examined by qualitative and quant...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2014.09.008
更新日期:2015-01-01 00:00:00
abstract::Counts of cultivable Porphyromonas gingivalis, assays of microbial proteases and the concentration in gingival crevicular fluid of proteoglycan metabolites were investigated at periodontitis and gingivitis sites in 16 patients with chronic adult periodontitis before and after treatment. Two periodontitis sites and two...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/s0003-9969(96)00103-3
更新日期:1997-01-01 00:00:00
abstract:OBJECTIVE:The existence of extra-pineal melatonin has been observed in various tissues. No prior studies of melatonin in human oral mucosal tissue under the condition of chronic inflammation have been reported. The aim of this study was to investigate the presence of melatonin in oral mucosal tissue of patients with or...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2017.02.007
更新日期:2017-06-01 00:00:00
abstract:OBJECTIVE:Biomarkers in gingival crevicular fluid (GCF) have been investigated; however, measurements were limited by the small sample volume available. The aim of this study was to determine the levels of 40 different cytokines and chemokines in GCF samples. DESIGN:Eleven patients with generalised chronic periodontit...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2012.11.012
更新日期:2013-06-01 00:00:00
abstract::Long non-coding RNAs (lncRNAs) have recently attracted more attention about the role in a broad range of biological processes and complex cancers. We aimed to identify differentially expressed lncRNAs that play an important role in the pathogenesis of oral squamous cell carcinoma (OSCC). Microarray data GSE25099 consi...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2015.08.003
更新日期:2015-10-01 00:00:00
abstract::The aim of this study was to investigate the potential effects of vitamin K1 supplementation on skeletal changes related to fluoride in growing rats. Forty male Wistar rats aged 4 weeks were assigned at random into three groups: high-dose fluoride (125 ppm) group; high-dose fluoride + vitamin K1 (0.2 mg/(g day)) group...
journal_title:Archives of oral biology
pub_type: 更正并重新发布的文章,杂志文章
doi:10.1016/j.archoralbio.2009.02.001
更新日期:2009-06-01 00:00:00
abstract::These immunoglobulins were quantitated in 303 individuals belonging to 37 negroid and 26 caucasoid American families. Levels varied widely from individual to individual and frequency distributions were skewed toward the low levels. IgA was detected in all individuals except three children; two of whom were young and t...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(88)90055-6
更新日期:1988-01-01 00:00:00
abstract::With scanning electron microscopy, globules were seen in inter-cellular spaces between ameloblasts with ruffled borders and papillary cells at early maturation stage. Numerous globules were located on longitudinal folds between parallel ridges on the sides of ameloblasts, but only a few in the papillary layer. In prev...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(84)90121-3
更新日期:1984-01-01 00:00:00
abstract::The aim was to examine the nature of enamel dissolution in aqueous suspensions with a high solid/solution ratio and in a CO2-rich atmosphere. Before experimentation, a water-saturated mixture of 95% N2-5% CO2 was passed through the acid solutions for 24 hr. Samples of 2 g of powdered enamel were suspended in 7 ml of e...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/s0003-9969(97)00043-5
更新日期:1997-09-01 00:00:00
abstract:OBJECTIVE:To investigate the effects of sitagliptin, a dipeptidyl peptidase 4 inhibitor used to treat type II diabetes, on bone tissue and on implant osseointegration in diabetic rats. DESIGN:Thirty-two male rats were divided into four groups: 1) Diabetic animals (GD); 2) Diabetic animals that received sitagliptin (GD...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2019.04.018
更新日期:2019-06-01 00:00:00
abstract::The aim of this study was to investigate the age-related developmental changes of taste bud distribution within the subpopulations at different postnatal ages in the mouse oral cavity. Developmental changes of taste bud distribution on the soft palate, fungiform, foliate and circumvallate papillae in the mouse oral ca...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2008.01.005
更新日期:2008-06-01 00:00:00
abstract::Prostaglandins are involved in force-induced orthodontic tooth movement. Bradykinin (BK) and thrombin are known to cause a significant time- and concentration-dependent burst of prostanoid biosynthesis in cultured human periodontal-ligament (PDL) cells. The aim now was to investigate interactive effects between interl...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/s0003-9969(98)00010-7
更新日期:1998-04-01 00:00:00
abstract::Recent studies of the manipulation and reduction of food in the human mouth have used lateral-projection videofluorography (VFG) and so have concerned antero-posterior food movement. To determine the degree to which (a) food was chewed bilaterally as opposed to unilaterally, (b) the frequency of side changes, (c) the ...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/s0003-9969(02)00007-9
更新日期:2002-04-01 00:00:00
abstract:OBJECTIVE:To test the association of child's growth/development status and socioeconomic variables with dental emergence patterns. DESIGN:A sample of 359 children belonging to a birth cohort of over 5000 children born in 1993 in Pelotas (Brazil) was studied in 1998-1999. Previously trained observers collected birthwei...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2006.12.001
更新日期:2007-06-01 00:00:00
abstract::The aim of this study was to compare total IgA in the whole saliva of children with Down syndrome with levels in sibling and parent groups. IgA measurements were presented as the concentration in saliva (μg/ml) and also adjusted for salivary flow rate (SFR; μg/min). Twenty children with Down syndrome, ten siblings and...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2016.03.005
更新日期:2016-07-01 00:00:00
abstract::The abrasiveness of food is a key determinant in the rate of physiological attrition (dental wear) in humans. With increasing food processing through time, the rate of physiological dental wear in human teeth has decreased markedly. Many consider such wear to be beneficial to oral health and that insufficient wear may...
journal_title:Archives of oral biology
pub_type: 历史文章,杂志文章
doi:10.1016/s0003-9969(99)00095-3
更新日期:1999-11-01 00:00:00
abstract::High-speed, high-resolution data (frontal plane) were collected from 6 Sprague-Dawley rats by opto-electronic mandibular tracking (OMT), followed by microcomputer analysis of individual chew cycles. Mastication comprised rapidly alternating, unilateral cycles with variable degrees of lateral translation. There was no ...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(88)90047-7
更新日期:1988-01-01 00:00:00
abstract::Green tea is a leading beverage in the Far East for thousands of years; it is regarded for a long time as a health product. Green tea is important source of polyphenol antioxidants. Polyphenols including epigallocatechin 3 gallate (EGCG) constitute the most interesting components in green tea leaves. Green tea has the...
journal_title:Archives of oral biology
pub_type: 杂志文章,评审
doi:10.1016/j.archoralbio.2011.11.017
更新日期:2012-05-01 00:00:00
abstract::The colonial variants of W50, derived after growth in a chemostat and previously designated W50/BP1, W50/BR1 and W50/BE1, produced black-, brown- and beige-pigmented colonies, respectively, and showed reductions in mouse virulence and proteolytic activity correlating with their reduced pigmentation. Incubation of glas...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(91)90037-u
更新日期:1991-01-01 00:00:00
abstract::An engineering model of the periodontal ligament fibres was used to calculate length changes in the fibres with: direct occlusal forces on the tooth, occlusal loads on other teeth in the arch and splinting. The fibre elongations appear to influence tooth eruption, the clinical behaviour of splinted and non-splinted te...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(88)90109-4
更新日期:1988-01-01 00:00:00
abstract::It is known that pulpal fluid movement through dentinal tubules causes dentinal hypersensitivity and that pain can be reduced by decreasing the fluid flow. The aim of this study was to evaluate dentinal permeability and morphology after a single exposure to experimental phytocomplex substances containing oxalates. The...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2006.02.010
更新日期:2006-08-01 00:00:00
abstract::These three neuropeptides were measured at daily baseline values by radioimmunoassay. Stimulated parotid saliva was collected from 31 subjects using a modified Carlson-Crittenden device affixed over Stenson's duct. Methionine enkephalin-like immunoreactivity ranged from 6.6 to 11.7 fmol/ml, with a mean of 9.3 fmol/ml....
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(92)90076-k
更新日期:1992-09-01 00:00:00
abstract::The effects of interleukin-1 (IL-1) on the metabolism of two androgenic substrates, testosterone and 4-androstenedione, that can be converted to the potent anabolic metabolite 5 alpha-dihydrotestosterone (DHT) were studied. Duplicate incubations of confluent gingival fibroblasts were made in Eagle's minimum essential ...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(95)00058-w
更新日期:1995-10-01 00:00:00
abstract:INTRODUCTION:Angiogenesis is important in pulp-dentin formation. Among the regulatory factors, long noncoding RNA (LncRNA) is a class of functional RNA molecules that are not translated into protein and involved in regulating multiple physiological processes. The different expression of LncRNA and its target gene in de...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/j.archoralbio.2020.104691
更新日期:2020-05-01 00:00:00
abstract::Mandibular first-molar tooth germs were dissected from 16-day-embryo and new-born CD1 mice. By incubation in collagenase they were separated into enamel organ, papilla and follicle. Dental pulp was obtained from mandibular first molars of 3-, 7- and 10-day-old mice. Various combinations of epithelial and mesenchymal t...
journal_title:Archives of oral biology
pub_type: 杂志文章
doi:10.1016/0003-9969(87)90022-7
更新日期:1987-01-01 00:00:00