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Wang BC. Regarding Dr. Steven's editorial. Reg Anesth Pain Med 1998; 23:112. [PMID: 9552793 DOI: 10.1016/s1098-7339(98)90125-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Yang CY, Lin RM, Wang BC, Lee TM, Chang E, Hang YS, Chen PQ. In vitro and in vivo mechanical evaluations of plasma-sprayed hydroxyapatite coatings on titanium implants: the effect of coating characteristics. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1997; 37:335-45. [PMID: 9368138 DOI: 10.1002/(sici)1097-4636(19971205)37:3<335::aid-jbm4>3.0.co;2-m] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study was undertaken to evaluate the effect of coating characteristics on the mechanical strengths of the plasma-sprayed HA-coated Ti-6Al-4V implant system both in vitro and in vivo. Two types of HA coatings (HACs) with quite different microstructures, concentrations of impurity-phases, and indices-of-crystallinity were used. In vitro testings were done by measuring the bonding-strength at the Ti-6Al-4V-HAC interface, with HACs that had and had not been immersed in a pH-buffered, serum-added simulated body fluid (SBF). The shear-strength at the HAC-bone interface was investigated in a canine transcortical femoral model after 12 and 24 weeks of implantation. The results showed a bonding degradation of approximately 32% or higher of the original strength after 4 weeks of immersion in SBF, and this predominantly depended on the constructed microstructure of the HACs. After the push-out measurements, it was demonstrated that the HACs with higher bonding-strength in vitro would correspondingly result in significantly higher shear-strength at each implant period in vivo. Nevertheless, there were no substantial histological variations between the two types of HACs evaluated. The most important point elucidated in this study was that, among coating characteristics, the microstructure was the key factor in influencing the mechanical stability of the HACs both in vitro and in vivo. As a consequence, a denser HAC was needed to ensure mechanical stability at both interfaces.
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Yang CY, Wang BC, Lee TM, Chang E, Chang GL. Intramedullary implant of plasma-sprayed hydroxyapatite coating: an interface study. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1997; 36:39-48. [PMID: 9212387 DOI: 10.1002/(sici)1097-4636(199707)36:1<39::aid-jbm5>3.0.co;2-m] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An intramedullary implant model in the canine femora was developed to evaluate the mechanical and histological responses between cancellous bone and plasma-sprayed hydroxyapatite coatings (HACs) on ti-6A1-4V implants, with 12- and 24-week follow-ups. HACs of different thicknesses were investigated. Results of the mechanical testings revealed that after 24 weeks of implantation, the mean shear strength (2.49 +/- 0.12 MPa) of the 50 microns HACs was significantly higher (p < 0.05) than that of the 200 microns HACs (1.44 +/- 0.19 MPa). However, using backscattered electron images (BEIs) throughout all the implant periods, no substantial histological variations in the extent of new bone apposition between the two HACs were observed. Occasionally, solution-mediated disintegration of the 50 microns HAC was found 24 weeks postimplantation. Histomorphometric studies from the BEIs demonstrated that for both HACs the percentage of the direct HAC-cancellous bone contact was approximately 50% at 12 weeks and 75% at 24 weeks. After the mechanical tests, the 200 microns HACs had fracture sites either inside the coating layers or at the HAC-titanium interfaces, which might explain why the mechanical performance of the 200 microns HACs was inferior to that of the 50 microns HACs even though both HACs had the same histological behaviors.
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Rose JP, Wu CK, Francavilla A, Prelich JG, Iacobellis A, Hagiya M, Rao AS, Starzl TE, Wang BC. Crystallization and preliminary crystallographic data for the augmenter of liver regeneration. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 1997; 53:331-4. [PMID: 15299939 PMCID: PMC2962559 DOI: 10.1107/s0907444996014084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A new cellular growth factor termed augmenter of liver regeneration (ALR) has been crystallized. ALR has been shown to have a proliferative effect on liver cells while at the same time producing an immunosuppressive effect on liver-resident natural killer cells and liver-resident mononuclear leukocytes. In addition, ALR appears to play an important role in the synthesis and stabilization of mitochondrial gene transcripts in actively regenerating cells. ALR crystals diffract to beyond 2 A resolution and belong to space group P2(1)2(1)2, with a = 125.1, b = 108.1 and c = 38.5 A. Based on four molecules per asymmetric unit, the Matthews coefficient is calculated to be 2.16 A(3) Da(-1) which corresponds to a solvent content of 43%.
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Liu ZJ, Sun YJ, Rose J, Chung YJ, Hsiao CD, Chang WR, Kuo I, Perozich J, Lindahl R, Hempel J, Wang BC. The first structure of an aldehyde dehydrogenase reveals novel interactions between NAD and the Rossmann fold. NATURE STRUCTURAL BIOLOGY 1997; 4:317-26. [PMID: 9095201 DOI: 10.1038/nsb0497-317] [Citation(s) in RCA: 246] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The first structure of an aldehyde dehydrogenase (ALDH) is described at 2.6 A resolution. Each subunit of the dimeric enzyme contains an NAD-binding domain, a catalytic domain and a bridging domain. At the interface of these domains is a 15 A long funnel-shaped passage with a 6 x 12 A opening leading to a putative catalytic pocket. A new mode of NAD binding, which differs substantially from the classic beta-alpha-beta binding mode associated with the 'Rossmann fold', is observed which we term the beta-alpha,beta mode. Sequence comparisons of the class 3 ALDH with other ALDHs indicate a similar polypeptide fold, novel NAD-binding mode and catalytic site for this family. A mechanism for enzymatic specificity and activity is postulated.
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Chang E, Chang WJ, Wang BC, Yang CY. Plasma spraying of zirconia-reinforced hydroxyapatite composite coatings on titanium: part II: dissolution behaviour in simulated body fluid and bonding degradation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 1997; 8:201-211. [PMID: 15348760 DOI: 10.1023/a:1018535606393] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The change of phase, morphology and bond strength of plasma sprayed hydroxyapatite (HA) coating and ZrO2/HA composite coatings immersed in simulated body fluid (SBF) for various periods of time was studied. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) were used to identify the phase and observe the morphology of the coating surface before and after immersion. In addition, inductively coupled plasma emission spectroscopy (ICP) was used to measure the ion release rate of coatings in SBF for various periods of time. Observation of the morphology by SEM shows that the composite coating with the addition of ZrO2 in HA significantly reduced the dissolution rate of impurity phases in simulated body fluid. The argument was supported by measurement of Ca2+ ion concentration in SBF. During plasma spraying, less OH- ions were lost in a ZrO2-containing composite coating. This factor, together with the reduced effective surface of the ZrO2-containing HA coating, were attributed to the reduced dissolution rate of the composite coatings. All the plasma sprayed coatings degraded after immersion in SBF owing to dissolution of constituents in the coating, however, the addition of ZrO2 in HA improved the bonding strength of HA coating after immersion in SBF.
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Chang E, Chang WJ, Wang BC, Yang CY. Plasma spraying of zirconia-reinforced hydroxyapatite composite coatings on titanium: part I: phase, microstructure and bonding strength. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 1997; 8:193-200. [PMID: 15348759 DOI: 10.1023/a:1018583522322] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Plasma-sprayed hydroxyapatite (HA) coatings applied to metal substrates can induce a direct chemical bond with bone and hence achieve biological fixation of the implant. However, the poor bonding strength between HA and substrate has been of concern to orthopaedists. In this study, two submicrometre ZrO2 powders stabilized with both 3 and 8 mol% Y2O3 (TZ3Y and TZ8Y, respectively) were incorporated in a plasma-sprayed HA coating on Ti-6Al-4V substrate to investigate the change in phase, microstructure and bonding strength. The results show that ZrO2 composite coatings contain more unmelted particles and greater porosity. During plasma spraying, ZrO2 reacts with the CaO in HA to form CaZrO3 and accelerates HA decomposition to alpha-TCP and Ca4P2O9. Nevertheless, bonding strength increases with increase of ZrO2 content in the range 0 to 10 wt% studied. The higher Y2O3-containing TZ8Y apparently exerts a greater strengthening effect than the lower Y2O3-containing TZ3Y.
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Hempel J, Liu ZJ, Perozich J, Rose J, Lindahl R, Wang BC. Conserved residues in the aldehyde dehydrogenase family. Locations in the class 3 tertiary structure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 414:9-13. [PMID: 9059601 DOI: 10.1007/978-1-4615-5871-2_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Liu ZJ, Hempel J, Sun J, Rose J, Hsiao D, Chang WR, Chung YJ, Kuo I, Lindahl R, Wang BC. Crystal structure of a class 3 aldehyde dehydrogenase at 2.6 A resolution. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 414:1-7. [PMID: 9059600 DOI: 10.1007/978-1-4615-5871-2_1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Hsiao CD, Sun YJ, Rose J, Wang BC. The crystal structure of glutamine-binding protein from Escherichia coli. J Mol Biol 1996; 262:225-42. [PMID: 8831790 DOI: 10.1006/jmbi.1996.0509] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The crystal structure of the glutamine-binding protein (GlnBP) from Escherichia coli in a ligand-free "open" conformational state has been determined by isomorphous replacement methods and refined to an R-value of 21.4% at 2.3 A resolution. There are two molecules in the asymmetric unit, related by pseudo 4-fold screw symmetry. The refined model consists of 3587 non-hydrogen atoms from 440 residues (two monomers), and 159 water molecules. The structure has root-mean-square deviations of 0.013 A from "ideal" bond lengths and 1.5 degrees from "ideal" bond angles. The GlnBP molecule has overall dimensions of approximately 60 A x 40 A x 35 A and is made up of two domains (termed large and small), which exhibit a similar supersecondary structure, linked by two antiparallel beta-strands. The small domain contains three alpha-helices and four parallel and one antiparallel beta-strands. The large domain is similar to the small domain but contains two additional alpha-helices and three more short antiparallel beta-strands. A comparison of the secondary structural motifs of GlnBP with those of other periplasmic binding proteins is discussed. A model of the "closed form" GlnBP-Gln complex has been proposed based on the crystal structures of the histidine-binding protein-His complex and "open form" GlnBP. This model has been successfully used as a search model in the crystal structure determination of the "closed form" GlnBP-Gln complex by molecular replacement methods. The model agrees remarkably well with the crystal structure of the Gln-GlnBP complex with root-mean-square deviation of 1.29 A. Our study shows that, at least in our case, it is possible to predict one conformational state of a periplasmic binding protein from another conformational state of the protein. The glutamine-binding pockets of the model and the crystal structure are compared and the modeling technique is described.
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Yang TS, Tsan SH, Wang BC, Chang SP, Ng HT. The evaluation of a new 7-day gonadotropin-releasing hormone agonist protocol in the controlled ovarian hyperstimulation for in vitro fertilization. J Obstet Gynaecol Res 1996; 22:133-7. [PMID: 8697342 DOI: 10.1111/j.1447-0756.1996.tb00955.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Gonadotropin-releasing hormone agonist (GnRHa) was used in the controlled ovarian hyperstimulation (COH) for the in vitro fertilization program. However, the traditional long protocol demanded more human menopause gonadotropin (hMG) and sometimes causes unnecessary delay in the procedure. A new 7-day GnRHa/hMG protocol required to conserve cost and time is thus evaluated for better outcome. METHODS Sixty consecutive IVF candidates less than 40 years of age were recruited for the study. Cases with severe male factor or polycystic ovarian disease were excluded. The perspective candidates were divided into two groups, one received the traditional, GnRHa2hMG protocol and the other received the new 7-day regimen. RESULTS When comparing the results in pregnancy rate (33.3% vs 30%), cleavage rate (75.7% vs 75.5%), and the number of oocyte obtained (5.96 +/- 0.91 vs 6.63 +/- 0.90), the 7-day GnRHa/hMG protocol is as good as those of the traditional regimen. The amount of hMG used nevertheless was significantly less (21.48 +/- 0.78 vs 50.59 +/- 2.07). CONCLUSIONS The new regimen will surely reduce the cost to relieve patient's financial burden and to increase patient's comfort.
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Rose JP, Wu CK, Hsiao CD, Breslow E, Wang BC. Crystal structure of the neurophysin-oxytocin complex. NATURE STRUCTURAL BIOLOGY 1996; 3:163-9. [PMID: 8564543 DOI: 10.1038/nsb0296-163] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The first crystal structure of the pituitary hormone oxytocin complexed with its carrier protein neurophysin has been determined and refined to 3.0 A resolution. The hormone-binding site is located at the end of a 3(10)-helix and involves residues from both domains of each monomer. Hormone residues Tyr 2, which is buried deep in the binding pocket, and Cys 1 have been confirmed as the key residues involved in neurophysin-hormone recognition. We have compared the bound oxytocin observed in the neurophysin-oxytocin complex, the X-ray structures of unbound oxytocin analogues and the NMR-derived structure for bound oxytocin. We find that while our structure is in agreement with the previous crystallographic findings, it differs from the NMR result with regard to how Tyr 2 of the hormone is recognized by neurophysin.
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Wang BC, Chang E, Lee TM, Yang CY. Changes in phases and crystallinity of plasma-sprayed hydroxyapatite coatings under heat treatment: a quantitative study. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1995; 29:1483-92. [PMID: 8600138 DOI: 10.1002/jbm.820291204] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
With three kinds of plasma-sprayed hydroxyapatite coatings (HACs) prepared, the objectives of this study were (1) to establish the calibration methods for quantitatively measuring the concentration of impurity phases and the degree of crystallinity of the HACs, and (2) to explore the effects of postheat treatments at various temperatures in vacuo on the changes of phases and crystallinity of the HACs. By the internal standard method used, the concentrations of impurity phases, such as alpha-TCP, beta-TCP, and TP, of the assprayed HACs were significantly higher than those measured by the direct intensity-ratio method, and the CaO phase was lower than the direct intensity-ratio method. When the HACs were heat treated in the temperature interval 630-850 degrees C, the concentrations of impurity phases obviously decreased, and the coating crystallinity apparently increased. After annealing at 850 degrees C, an HAC consisting of at least 95% crystallinity with few impurity phases was obtained. As the annealing temperatures in the interval 850-1000 degrees C were applied, however, the HA phase seriously decomposed, resulting in the appearance of a large number (higher than 20 wt%) of impurity phases in the HACs. This work suggests that the optimum heat treatment conditions in vacuo for maximizing crystallinity and minimizing impurity phases of the HACs do not occur at the same temperature.
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Yang TS, Wang BC, Chang SP, Ng HT. Comparison of human menopausal gonadotropin and follicle-stimulating hormone with gonadotropin-releasing hormone agonist desensitization for controlled ovarian hyperstimulation in in vitro fertilization. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1995; 55:452-6. [PMID: 7634183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND A pregnancy in patients treated with gonadotropin-releasing hormone agonists (GnRHa) using follicle-stimulating hormone (FSH) alone was first reported by Shaw et al. in 1991. Recently, several comparative trials have shown that FSH is as effective as human menopausal gonadotropin (hMG) in this indication. In other words, the residual endogenous levels of luteinizing hormone (LH) in GnRHa treated cycles may be generally sufficient to support FSH-induced follicular development to exempt from the co-administration of exogenous LH. METHODS A total of 42 consecutive candidates for in vitro fertilization (IVF) participated in a prospective randomized study. In this study, the efficacy of two different gonadotropins (Pergonal and Metrodin, Serono, Italy) in inducing ovulation was investigated. All treated women were less than 40 years of age and had received a long desensitized protocol by a GnRHa (Leuprolide acetate, Takeda or Decapeptyl, Ferring). Ovarian inactivity was monitored by plasma estradiol and LH concentration. After the pituitary gland was down-regulated, all patients were given either hMG (n = 25) or FSH (n = 17) for controlled ovarian hyperstimulation (COH). RESULTS The mean number of gonadotropin ampoules and the peak estradiol level were significantly higher in hMG group than in the FSH group. No significant differences were found between both groups in the incidence of cancelled cycles, failed oocyte recovery, mean number of oocytes recovered per patient, the fertilization and embryo cleavage-rate. However, the hMG group demonstrated a higher pregnancy and abortion rate. CONCLUSIONS There is no significant difference between hMG and FSH stimulation when used following GnRHa desensitization for COH, so the cost should be considered.
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Sun J, Hempel J, Lindahl R, Perozich J, Rose J, Wang BC. Progress toward the tertiary structure of (class 3) aldehyde dehydrogenase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1995; 372:71-7. [PMID: 7484412 DOI: 10.1007/978-1-4615-1965-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Wang BC, Li D, Hiller JM, Hillman DE, Pasternack BS, Turndorf H. The antinociceptive effect of S-(+)-ibuprofen in rabbits: epidural versus intravenous administration. Anesth Analg 1995; 80:92-6. [PMID: 7802308 DOI: 10.1097/00000539-199501000-00016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This study was designed to determine whether systemic absorption plays any role in the antinociceptive effect of epidural (EP) sodium S(+)-ibuprofen (IB). One week after surgical implantation of EP catheters, six rabbits were given EP injections with either normal saline (NS) 0.4 mL or IB 10 mg in 0.4 mL NS (Group 1) on separate days. Each animal was injected with IB 10 mg intravenously (i.v.) on another day. Six control rabbits (Group 2) had neither surgery nor any injection. Analgesic testing was performed using electric stimulation through two electrocardiogram (ECG) skin electrodes with built-in adhesive, attached to shaved hip areas using 50 V, 1 Hz, 3 ms, before and 0.5,1,2 and 3 h after injection in Group 1, and in similar times in controls. The 95% confidence intervals (CI) of the mean difference between baseline and maximal nociceptive response latency of all groups were compared using analysis of covariance (ANCOVA) adjusted for baseline measurements. This comparison covered all possible pairs among all groups. Significant antinociceptive effects were seen after EP IB but not after control or i.v. IB. Neither motor dysfunction nor evidence of systemic toxicity or neurotoxicity was observed in any animal.
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Sousa R, Rose J, Wang BC. The thumb's knuckle. Flexibility in the thumb subdomain of T7 RNA polymerase is revealed by the structure of a chimeric T7/T3 RNA polymerase. J Mol Biol 1994; 244:6-12. [PMID: 7966322 DOI: 10.1006/jmbi.1994.1699] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have solved the structure of a chimeric T7/T3 RNA polymerase (RNAP) in an orthorhombic crystal by molecular replacement with the T7 RNAP structure determined from a monoclinic crystal. The structure of the protruding "thumb" subdomain of the polymerase appears very different in these two crystals apparently because of differences in packing contacts made by the thumb subdomain. These observations support the proposal that the thumb subdomain is flexible and can wrap around bound template to obstruct polymerase: template dissociation during processive synthesis.
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Zeng K, Rose JP, Chen HC, Strickland CL, Tu CP, Wang BC. A surface mutant (G82R) of a human alpha-glutathione S-transferase shows decreased thermal stability and a new mode of molecular association in the crystal. Proteins 1994; 20:259-63. [PMID: 7892174 DOI: 10.1002/prot.340200306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A chimeric enzyme (GST121) of the human alpha-glutathione S-transferases GST1-1 and GST2-2, which has improved catalytic efficiency and thermostability from its wild-type parent proteins, has been crystallized in a space group that is isomorphous with that reported for crystals of GST1-1. However, a single-site (G82R) mutant of GST121, which exhibits a significant reduction both in vitro and in vivo in protein thermostability, forms crystals that are not isomorphous with GST1-1. The mutant protein crystallizes in space group P2(1)2(1)2(1), with cell dimensions a = 49.5, b = 92.9, c = 115.9 A, and one dimer per asymmetric unit. Preliminary crystallographic results show that a mutation of the surface residue Gly 82 from a neutral to a charged residue causes new salt bridges to be formed among the GST dimers, suggesting that the G82R mutant might aggregate more readily than does GST121 in solution, resulting in a change of its solution properties.
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Hsiao CD, Sun YJ, Rose J, Cottam PF, Ho C, Wang BC. Crystals of glutamine-binding protein in various conformational states. J Mol Biol 1994; 240:87-91. [PMID: 8021944 DOI: 10.1006/jmbi.1994.1420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Crystals of glutamine-binding protein (GlnBP) in various conformational states have been obtained. Crystals of the ligand-free "open" state (denoted form B) have unit cell dimensions a = 86.3 A, b = 86.3 A, c = 81.5 A, alpha = beta = gamma = 90 degrees and diffract to about 2.3 A resolution. An analysis of the intensity data using an Requiv plot indicates that the crystal system is orthorhombic, space group P2(1)2(1)2(1). Crystals of the ligand-bound "open" state (form B*) are obtained by soaking form B crystals with glutamine (Gln) and diffract to about 1.9 A. Crystals of the GlnBP-Gln complex in a ligand-bound "closed" state (form C) belong to space group P2(1)2(1)2(1) with a = 62.0 A, b = 65.7 A and c = 121.8 A and diffract to about 2.3 A. Crystals of a selenomethionyl GlnBP (form B') are isomorphous to form B crystals and diffract to about 2.1 A resolution.
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Ago H, Habuka N, Kataoka J, Furuno M, Tsuge H, Noma M, Miyano M, Wang BC, Xuong NH. Improved crystals of the toxic protein MAP by protein engineering towards the host specificity. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1994; 50:404-7. [PMID: 15299393 DOI: 10.1107/s0907444994002325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mirabilis anti-viral protein (MAP) is a ribosome-inactivating protein from Mirabilis jalapa L. Since MAP is effective over a broad spectrum of species, the protein is difficult to express in heterologous hosts such as Escherichia coli. Recently, we obtained a MAP mutant, Y72F which exhibits a lower (1/100) activity against E. coli ribosomes while retaining almost full activity against mammalian cells [Habuka, Miyano, Kataoka, Tsuge & Noma (1992). J. Biol. Chem. 267, 7758-7760]. For the crystallographic studies, the Y72F MAP expression vector with an OmpA leading sequence was constructed and expressed in E. coli. The Y72F MAP mutant was then isolated and purified from the cell culture medium. Crystals were grown using the crystallization conditions for the native MAP crystals [Miyano et al. (1992). J. Mol. Biol. 226, 281-283]: 50% ammonium sulfate containing 50 mM ammonium citrate and 2 mM adenine sulfate, pH 5.4. The crystals belong to space group P3(1)21 (or P3(2)21) with a = b = 104.1 and c = 134.3 A. The crystals are isomorphous with the wild-type crystals but diffract to higher resolution. Imaging-plate photographs of the Y72F mutant showed sharp intense spots without the streaking observed in the native crystals.
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Fu JH, Rose J, Tam MF, Wang BC. New crystal forms of a μ-class glutathione S-transferase from rat liver. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1994; 50:219-24. [PMID: 15299462 DOI: 10.1107/s0907444993009370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Two new crystal forms of isoenzyme 3-3 of rat liver glutathione S-transferase (GST 3-3) have been obtained. They were grown under essentially the same crystallization conditions as those reported for the C2 crystal form [Fu, Rose, Chung, Tam & Wang (1991). Acta Cryst. B47, 813-814]. The new crystals belong to space group P2(1) with one form having cell dimensions a = 101.6, b = 69.5, c = 81.4 A, and beta = 113.6 degrees, and the other form having cell parameters a = 97.4, b = 81.1, c = 69.4 A and beta = 109.2 degrees. These new crystals diffract to at least 2.5 A, resolution. The molecular packing arrangements in these P2(1) crystals have been found by molecular replacement studies.
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Wang BC, Rose J, Arents G, Moudrianakis EN. The octameric histone core of the nucleosome. Structural issues resolved. J Mol Biol 1994; 236:179-88. [PMID: 8107103 DOI: 10.1006/jmbi.1994.1127] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The crystal structure of the histone octamer has now been determined at 3.1 A resolution and refined to a crystallographic R value of 25.5%. The overall shape of the structure is significantly different from that originally reported by Burlingame et al. and its length is now in agreement with that observed by Klug et al. in their low-resolution studies. The experimental intensity data used in constructing the new electron density map were the same as those used by Burlingame et al. for the original electron density map. In addition, the methods used in producing the new density map were also the same as those for the original map. The only difference between the two calculations was the selection of the heavy-atom location. The large change seen in the structural image (110 A x 70 A x 70 A versus 55 A x 70 A x 70 A) was due to a relatively small change (2.27 A shift) of the heavy-atom site. The fact that the shape and size of the original structure were incorrect is surprising and unusual, since the electron density map that produced the original model was clear for most parts of the structure; one could easily see the well-formed right-handed helices of the H2A and H2B molecules, and the ordered parts of the H2A and H2B molecules could be easily traced from end to end. A comparison of the two maps shows that the original image was derived from two fused copies of the correct structure rotated by +/- 120 degrees from its true location along a rotation axis parallel to the z-axis and the image seen was a partial (about 19.5%) overlap of two molecules. An explanation is given as to how such a small shift of the heavy-atom position could create such a double image in the unit cell, and how the original electron density map could be converted to the new map by a phase modification in the Fourier synthesis. This study resolves the differences between the analyses of the shape and size of the histone octamer structure.
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Wang BC, Li D, Budzilovich G, Hiller JM, Rosenberg C, Hillman DE, Turndorf H. Antinociception without motor blockade after subarachnoid administration of S-(+)-ibuprofen in rats. Life Sci 1994; 54:715-20. [PMID: 8107521 DOI: 10.1016/0024-3205(94)90160-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study was designed to determine whether the nonsteroidal anti-inflammatory drug (NSAID) sodium S-(+)-ibuprofen (IB), can be used intrathecally as a substitute analgesic for opiates to avoid the side effects of intrathecal narcotics. One week or more after surgical implantation of subarachnoid catheters, four groups of Sprague-Dawley rats were given 0.05 ml subarachnoid injections containing one of the following: Group A, normal saline (NS); Group B, IB 0.25 mg, 0.5 mg and 1.5 mg; Group C, morphine (M) 0.05 mg and 0.025 mg; Group D received NS or IB 1.5 mg. Animals were sacrificed for spinal cord examination one week after injection. Tail flick response latency (TFL) was determined before and 15, 30, 60, 120 and 180 minutes after each injection. TFL differences were compared. IB 1.5 mg vs NS, IB 0.5 mg vs NS, IB 0.25 mg vs M 0.05 mg, IB 0.25 mg vs M 0.025 mg, M 0.05 mg vs NS, and M 0.025 vs NS showed p < 0.05. IB 1.5 mg vs M 0.05 mg and M 0.025 mg, IB 0.5 mg vs M 0.05 mg and M 0.025 mg revealed no significant difference. No motor impairment was observed in any animal. Light microscopy of the spinal cord revealed no evidence of pathological changes in any animal (group D).
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Kuwert T, Lange HW, Boecker H, Titz H, Herzog H, Aulich A, Wang BC, Nayak U, Feinendegen LE. Striatal glucose consumption in chorea-free subjects at risk of Huntington's disease. J Neurol 1993; 241:31-6. [PMID: 8138819 DOI: 10.1007/bf00870669] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Controversial data have been reported with regard to the diagnostic value of the positron emission tomographic (PET) measurement of striatal glucose consumption (rCMRGlc) in chorea-free subjects at risk of Huntington's disease (HD). For further clarification of this issue we measured striatal and cerebellar rCMRGlc in 27 chorea-free subjects at risk of HD, 20 patients with manifest HD and 20 control subjects, using PET and 18F-fluorodeoxyglucose. In 6 of the at-risk subjects cerebellar ratios of striatal rCMRGlc were decreased below the corresponding 99% confidence limit determined in the controls. This indicates that the PET measurement of rCMRGlc may, indeed, be valuable in establishing the diagnosis of incipient HD in presymptomatic at-risk subjects.
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Wang BC, Lee TM, Chang E, Yang CY. The shear strength and the failure mode of plasma-sprayed hydroxyapatite coating to bone: the effect of coating thickness. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1993; 27:1315-27. [PMID: 8245046 DOI: 10.1002/jbm.820271012] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Plasma-sprayed hydroxyapatite coated (HAC) 50 and 200 microns thick on Ti-6Al-4V cylinders was transcortically implanted in the femora of canines to evaluate in detail the effect of coating thickness on the pushout shear strength and failure mode examined under scanning electron microscope after the periods of 4, 6, 8, and 12 weeks. The HAC coating exhibited higher shear strength at 50 microns than at 200 microns. Its failure mode was conclusively at or near the HAC-bone interface, and the slight attack of body fluid had not degraded the implant to the extent that failure occurred at the HAC-Ti alloy interface after 12 weeks of observation. For 200 microns-HAC, failure was found at the HAC-bond interface, inside the HAC lamellar splat layer and at the HAC-Ti alloy substrate interface, depending on the period of implantation. It was also deduced that the variation of failure mode of 200 microns-HAC with time could not be accounted for by the attack of body fluid alone; the degradation must be a synergetic adverse result of residual stress in the HAC and the attack of body fluid.
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