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Biosynthesis and in vitro translation of the major surfactant-associated protein from human lung 总被引:10,自引:0,他引:10
We have characterized a 32,000-36,000-dalton sialoglycoprotein group that is an integral component of the lipoprotein complex called pulmonary surfactant. Our results from the cell-free translation of human lung RNA show that this protein consists of two similarly-sized precursor components of about 29,000-31,000 daltons. Tunicamycin treatment of the lung tissue prevents formation of the normal protein and results in the accumulation of these precursor components which are also seen under normal conditions in very small amounts. Although in vitro translation in the presence of dog pancreatic microsomes suggests that a cleavable signal peptide sequence is present in these precursor molecules, it does not appear that this cleavage occurs in vivo. 相似文献
4.
P V Phelps F W Edens V L Christensen 《Comparative biochemistry and physiology. A, Comparative physiology》1987,86(4):745-750
Packed cell volume, total leukocytes, total erythrocytes, hemoglobin, mean cell volume and mean corpuscular hemoglobin concentration of the poult were analyzed daily for the first 10 days posthatch. Sexually dimorphic effects on hematological parameters were not apparent, but there was a sex X day interaction for all parameters except hemoglobin indicating that males were slower to develop/respond to critical stimuli. The study revealed a latency in production of erythrocytes and leukocytes in posthatch males and females which coincided temporally with early poult mortality. 相似文献
5.
Successful infection of the common marmoset (Callithrix jacchus) with human varicella-zoster virus. 总被引:1,自引:0,他引:1 下载免费PDF全文
P J Provost P M Keller F S Banker B J Keech H J Klein R S Lowe D H Morton A H Phelps W J McAleer R W Ellis 《Journal of virology》1987,61(10):2951-2955
The common marmoset, Callithrix jacchus, can be infected with human varicella-zoster virus (VZV), both wild-type strain KMcC and attenuated vaccine strain Oka/Merck. Infection was accomplished with either whole-cell-associated or cell extract VZV by combined oral-nasal-conjunctival application and was characterized by substantial and persistent anti-VZV antibody responses. The infectivity of VZV for marmosets was destroyed by treatment of inocula with heat or UV light. Diluted inocula with as few as 40 PFU/ml were infectious for marmosets. The lungs were demonstrated to be a major site of viral replication; both the presence of viral antigens and signs of pneumonia were demonstrated in lung tissues. Four serial passages of VZV KMcC were carried out in C. jacchus by a process of in vitro isolation and culturing of VZV from infected lung tissue and reapplication of the cultured isolates to fresh animals. The isolated viruses were identified as VZV both serologically and by restriction endonuclease analyses. The C. jacchus infectivity model should prove useful for determining the efficacy of subunit and live recombinant VZV vaccines as well as for the study of zoster. 相似文献
6.
Sublethal amounts of amphotericin B inhibited the interaction of Candida albicans with cultured fibroblasts. Different C. albicans clinical isolates exhibited varying degrees of sensitivity to the drug, but those isolates that were the most infective in control cultures appeared to be the most resistant to amphotericin B mediated infection inhibition. Although amphotericin B inhibited germ tube formation at the sublethal concentration of 0.3 microgram/mL, lower concentrations inhibited infection without preventing germination. The extent of this latter activity varied with the isolate and amphotericin B concentration and appeared to be related to sublethal effects on germinated yeasts. While amphotericin B effectively prevented new fibroblast infection, it did not dissociate those yeasts which had established an infection before its addition. 相似文献
7.
Dr. John L. Johnson Carol Phelps Lisa Barroso Mary D. Roberts David M. Lyerly Tracy D. Wilkins 《Current microbiology》1990,20(6):397-401
Results from our cloning studies on toxin A indicated that the gene for toxin B resided approximately 1 kb upstream of the toxin A gene. Clone pCD19, which contains the 5-end of the toxin A gene and a small open reading frame, was found to contain 1.2 kb of DNA which, when subcloned, expressed a nontoxic peptide that reacted with toxin B antibodies. The rest of the toxin B gene was located on the 6.8 kb cloned fragment of plasmid pCD19L. The two fragments overlapped 0.8 kb. Lysates containing protein expressed by the 6.8 fragment were cytotoxic and lethal, and were neutralized by toxin B antibody. The two fragments were ligated to give the complete toxin B gene. The protein expressed by the complete gene was cytotoxic and lethal, and showed complete immunological identity with toxin B. Further analysis of the expressed protein and the toxin B gene confirmed our earlier findings showing that toxin B has a molecular weight of 240,000 or greater. 相似文献
8.
T J Phelps K Malachowsky R M Schram D C White 《Applied and environmental microbiology》1991,57(4):1252-1254
A gram-positive branched bacterium isolated from a trichloroethylene-degrading consortium mineralized vinyl chloride in growing cultures and cell suspensions. Greater than 67% of the [1,2-14C]vinyl chloride was mineralized to carbon dioxide, with approximately 10% of the radioactivity appearing in cell biomass and another 10% appearing in 14C-aqueous-phase products. 相似文献
9.
Mineralization of Trichloroethylene by Heterotrophic Enrichment Cultures 总被引:16,自引:14,他引:2 下载免费PDF全文
C. B. Fliermans T. J. Phelps D. Ringelberg A. T. Mikell D. C. White 《Applied microbiology》1988,54(7):1709-1714
Microbial consortia capable of aerobically degrading more than 99% of exogenous trichloroethylene (TCE) (50 mg/liter) were collected from TCE-contaminated subsurface sediments and grown in enrichment cultures. TCE at concentrations greater than 300 mg/liter was not degraded, nor was TCE used by the consortia as a sole energy source. Energy sources which permitted growth included tryptone-yeast extract, methanol, methane, and propane. The optimum temperature range for growth and subsequent TCE consumption was 22 to 37°C, and the pH optimum was 7.0 to 8.1. Utilization of TCE occurred only after apparent microbial growth had ceased. The major end products recovered were hydrochloric acid and carbon dioxide. Minor products included dichloroethylene, vinylidine chloride, and, possibly, chloroform. 相似文献
10.
The binding of 25-hydroxy-[26,27-3H]vitamin D-3 and 25-hydroxy-[26,27-3H]vitamin D-2 to the vitamin D binding protein in the plasma of both rats and chicks has been studied. In the case of rats, sucrose density gradient analysis, competitive displacement, and Scatchard analysis demonstrate that 25-hydroxyvitamin D-3 and 25-hydroxyvitamin D-2 are bound equally well to the vitamin D binding protein. In contrast, 25-hydroxyvitamin D-2 is poorly bound, while 25-hydroxyvitamin D-3 is tightly bound to the vitamin D binding protein in chick plasma. On the other hand, the chick intestinal receptor binds 1,25-dihydroxyvitamin D-2 and 1,25-dihydroxyvitamin D-3 equally well with a KD of 7.10(-11) M for both compounds. These results strongly suggest that the failure of the plasma transport protein in chicks to bind the vitamin D-2 compounds may be responsible for their relative ineffectiveness in these animals. 相似文献