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Bovine seminal plasma contains three similar acidic proteins, which we have previously designated as BSP-A1, BSP-A2, and BSP-A3. These proteins contain two homologous domains that are similar to type II structures present in the gelatin-binding domain of fibronectin. The present data have revealed that these proteins, like fibronectin, also form complexes with gelatin, a denatured collagen. Based on this property, a single step affinity purification method has been developed. In addition to these three proteins BSP-A1, -A2 and -A3, another protein with an apparent molecular weight of 30,000 dalton (named BSP-30-kDa) also bound to the gelatin-agarose column. Elution of these proteins from affinity columns using a linear gradient of either urea or arginine gave essentially the same pattern with a high yield of 90–95%. The purified proteins were homogeneous by SDS-polyacrylamide gel electrophoresis, amino acid composition and HPLC. Chromatography of bull seminal vesicular fluid also exhibited an elution pattern similar to that obtained for bull seminal plasma. The availability of these purified proteins should aid in understanding the physiology of these gelatin-binding proteins. 相似文献
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The mean dimensions of thecis N-methyl peptide unit have been arrived at by analysing the crystal structure data on compounds containing such units. These
dimensions can be used as standard in conformational studies on cyclic peptides. While the bonds meeting at C are almost coplanar,
those meeting at N show a slight pyramidal disposition. A comparison of the dimensions of the normal and N-methylatedcis peptide units show that there are perceptible differences in the parameters connected with N. In addition, the flexibility
of thecis peptide unit has been analysed by studying the distribution of the parameters in different classes of compounds such as cyclic
di, tri and higher peptides. The salient features are: (i) The angle CαCN in cyclic dipeptide and the angle CδNCα in higher peptides tend to be lower, when the peptide unit is associated with a prolyl residue; (ii) in cyclic tripeptides
the internal anglesviz., CαCN and CNCα are significantly larger thereby increasing the intra-annular space; (iii) the bond Cα-C is distinctly shorter when it occurs in cyclic dipeptides. The results lead to the conclusion that thecis peptide unit takes up aneed-based flexibility in its dimension. 相似文献
7.
Non-pathogenic, environmental strain ofVibrio cholerae, ELTOR Ogawa EW6 carries a copy of the cholera toxin gene in its chromosome. Restriction enzyme digestion followed by Southern
blot analysis revealed that the structure of the cholera toxin gene in this organism is different from that found in the virulent
strains. The xbaI site which has been found to be conserved in the cholera toxin of the virulent strains examined so far,
is absent here. Results of the RNA dot blot analysis indicated that the cholera toxin gene in EW6 is transcribed much less
efficiently compared to the cholera toxin gene present in the virulent strainVibrio cholerae classical Inaba 569B. 相似文献
8.
K Uma P Balaram P Kaur A K Sharma V S Chauhan 《International journal of biological macromolecules》1989,11(3):169-171
Two tripeptides of the type Boc-Pro-delta ZX-Gly-NHEt (where X = Leu, Phe) have been synthesized and their solution conformations investigated by 270 MHz 1H n.m.r. and i.r. spectroscopy. These conformational studies indicated that delta ZLeu, similar to delta ZPhe, has a strong tendency to stabilize folded Type II beta-turn conformations when present at i + 2 position. 相似文献
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M S Jawahar S Sivasubramanian V K Vijayan C V Ramakrishnan C N Paramasivan V Selvakumar S Paul S P Tripathy R Prabhakar 《BMJ (Clinical research ed.)》1990,301(6748):359-362
OBJECTIVE--To assess the efficacy of a short course chemotherapy regimen for treating tuberculosis of the lymph nodes in children. DESIGN--Open, collaborative, outpatient clinical trial. SETTING--Outpatient department of the Tuberculosis Research Centre, paediatric surgery departments of the Institute of Child Health and Hospital for Children and the Government Stanley Hospital, Madras, South India. PATIENTS--Children aged 1-12 years with extensive, multiple site, superficial tuberculous lymphadenitis confirmed by biopsy (histopathology or culture). INTERVENTIONS--Patients were treated with a fully supervised intermittent chemotherapy regimen consisting of streptomycin, rifampicin, isoniazid, and pyrazinamide three times a week for two months followed by streptomycin and isoniazid twice a week for four months on an outpatient basis. Surgery was limited to biopsy of nodes for diagnosis and assessment. MAIN OUTCOME MEASURES--Response to chemotherapy was assessed by regression of lymph nodes and healing of sinuses and abscesses during treatment and follow up. Compliance with treatment and frequency of adverse reactions were also estimated. RESULTS--197 Patients were admitted to the study and 168 into the analysis. The regimen was well tolerated and compliance was good with 101 (60%) patients receiving the prescribed chemotherapy within 15 days of the stipulated period of six months. Those whose chemotherapy extended beyond that period received the same total number of doses. Clinical response was favourable in most patients at the end of treatment. Sinuses and abscesses healed rapidly. Residual lymphadenopathy (exceeding 10 mm diameter) was present in 50 (30%) patients at the end of treatment; these nodes were biopsied. Fresh nodes, increase in size of nodes, and sinuses and abscesses occurred both during treatment and follow up. After 36 months of follow up after treatment only 5 (3%) patients required retreatment for tuberculosis. CONCLUSION--Tuberculous lymphadenitis in children can be successfully treated with a short course chemotherapy regimen of six months. 相似文献
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Administration of low amounts of ethanol for a prolonged period increases rat brain synaptosomal (Na+–K+)-ATPase activity, the increase being less in the protein deficient rats. The adaptive mechanism to offset the stress imposed by the continued presence of ethanol seems to be depressed by low plane of nutrition. In vivo and in vitro effects of ethanol on (Na+–K+)ATPase seems to be different. 相似文献