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41.
A cytoplasmic thyroid hormone binding protein: characterization using monoclonal antibodies 总被引:1,自引:0,他引:1
We have previously purified a cellular thyroid hormone binding protein (p58) from a human carcinoma cell line [Kitagawa, S., Obata, T., Hasumura, S., Pastan, I., & Cheng, S.-y. (1987) J. Biol. Chem. 262, 3903-3908]. In the present study, the binding characteristics, the molecular properties, and subcellular localization of p58 were further characterized. Binding of the purified p58 to thyroid hormones was examined. Analysis of binding data indicates that p58 binds to 3,3',5-triiodo-L-thyronine (T3) with a Kd of 24.3 +/- 0.3 nM and n = 0.71. p58 binds to L-thyroxine similarly as to T3. However, D-T3 and reverse-T3 bind to p58 with an affinity 4- and 20-fold less than that of T3, respectively. By use of the purified p58 as an immunogen, two hybridomas, J11 and J12, secreting monoclonal antibodies to p58 were isolated; both antibodies belong to the IgG1K subclass. J12 recognizes p58 from human, monkey, dog, hamster, and rat, but not mouse. J11 exhibits a similar species specificity except that it does not react with p58 from hamster. With these antibodies, p58 was found to be not posttranslationally modified by glycosylation, sulfation, or phosphorylation. It has a cellular degradation rate t1/2 congruent to 2.1 h. Immunocytochemical studies indicate that p58 is located in the nonmembranous cytoplasm (cytosol). These results are consistent with subcellular fractionation studies which show that greater than 95% of J11 and J12 reactivity and T3 binding activity can be found in the 110,000g supernatant. 相似文献
42.
43.
Decarboxylation of uroporphyrinogen III by erythrocyte uroporphyrinogen decarboxylase. Evidence for a random decarboxylation mechanism. 下载免费PDF全文
The isomeric composition of type-III heptacarboxylic porphyrinogens derived from decarbosylation of uroporphyrinogen III by erythrocyte uroporphyringogen decarboxylase was analysed by h.p.l.c. with electrochemical detection. All four possible isomers were identified, and there were little differences in the proportion of isomers formed by erythrocytes from normal subjects and from patients with sporadic porphyria cutanea tarda. The results provide conclusive evidence that the normal decarboxylation pathway is random in nature, and the fourth isomer only increases when enzyme abnormality is found. 相似文献
44.
Liang Zhong Chen Simon Easteal Philip G. Board Kim M. Summers Kuldeep K. Bhatia Robert L. Kirk 《Human genetics》1990,85(1):89-97
Summary We have determined the various haplotypic combinations between alleles as well as restriction fragment length polymorphisms of two linked genetic markers, albumin and vitamin D-binding protein or group-specific component, in a number of Asian-Pacific populations. Using the partial maximum likelihood method, we constructed a phylogenetic network from the haplotype frequencies to assess relationships among the populations sampled. No systematic linkage disequilibrium was detected between most of the combinations, suggesting a lack of operation of any selection pressure at the two loci. The phylogenetic analysis confirmed the known interrelationships among various populations in the Asian-Pacific region. The Australian aborigines clustered closely with the non-Austronesian-speaking highlanders from Papua New Guinea, as expected. Similarly, the Austronesian-speaking Polynesians, Micronesians, and the Southeast Asians branched off together as a separate group. The position of the Austronesian-speaking Tolais from New Britain with respect to other populations from the Southwest Pacific was anomalous. The Tolais revealed a strong affinity with the Australian aborigines, which is inexplicable. The populations from China formed a tight cluster with other populations from the Asian-Pacific region. Genetic interrelationships of these populations with the white Australians were remote, which is in accordance with the known affinities of various human racial groups. 相似文献
45.
原生质体来源的大白菜 Brasstca campessris var.pekinsis 悬浮细胞系在二甲亚砜的保护下,能在液氮中(-196℃)长期冻存。加入山梨醇能增强保护作用;而加入甘露糖则降低保护作用。培养基对冻存也有明显的影响。在液氮中存放的时间长短对细胞存活率没有多大影响。冻后相对活性最高可达75.4%,恢复生长快,化冻后重新悬浮培养6天,生长量可达300-500%。遮光比不遮光对恢复更有利。冻存后恢复生长的悬浮细胞,能与未经冰冻的对照一样进行原生质体分离和培养。 相似文献
46.
Forty different chiral molecules were studied by liquid chromatography with a Pirkle-type, (R)-N-(3,5-dinitrobenzoyl) phenylglycine (DNBPG), chiral stationary phase column. The dramatic effect of a small molecular change on chiral recognition was demonstrated using DL-amino acid derivatives. The inductive effect on chiral recognition was also studied using trifluoro-, trichloro-, dichloro-, monochloroacetyl, and acetyl derivatives of four different chiral amines. The study of the enantiomer separation of 11 different crown ethers of 2,2′-binaphthyldiyl showed that the rigidity of the chiral center can be an additional parameter in chiral recognition for the DNBPG phase but not for a β-cyclodextrin bonded chiral phase. It is apparent from this study that steric effects, inductive effects, and molecular rigidity play important roles in chiral recognition with DNBPG chiral stationary phases. 相似文献
47.
Tissue specific expression of avian vitellogenin gene is correlated with DNA hypomethylation and in vivo specific protein-DNA interactions 总被引:1,自引:0,他引:1
48.
烟草抗黑胫病突变体的细胞筛选 总被引:13,自引:1,他引:12
经实验我们成功地建立了在细胞水平上筛选烟草抗黑胫病突变体的筛选体系。该体系的主要内容为:γ-射线500—2000拉德诱变高度感病品种的花药后用50—80%的黑胫病菌粗毒素为选择压力,筛选出抗毒素花粉植株,用离体叶片法测定选出抗病植株,再从后代鉴定中选出抗病性能够稳定遗传的突变系。γ-射线及高浓度毒素处理均能得到抗病植株。选自感病品种的花粉植株中约有9—50%是真正抗病的。这些抗病植株中有一部分的抗病性能够稳定遗传。用该法已从感病优质品种小黄金1025及乔庄黑苗中选出6个突变系。并自N.C.628(抗)×小黄金1025(感)及N.C.628(抗)×庆胜2号(感)的F_1花粉植株中选出4个抗病系。所有的抗病系经3—4代后均表现出稳定抗性。其中一个突变体(R400)的抗性似由不完全显性多基因控制。 相似文献
49.
50.
Applied anatomy of the anterolateral femoral flap 总被引:13,自引:0,他引:13
D C Xu S Z Zhong J M Kong G Y Wang M Z Liu L S Luo J H Gao 《Plastic and reconstructive surgery》1988,82(2):305-310
A study of the source of the blood supply to the anterolateral femoral flap was carried out on 42 lower limbs of adult cadavers (among them 35 cadavers with injection of red latex and 1 with india ink into the arteries and 6 vascular cast specimens), and the surface locations of the vascular pedicle were detected on 50 healthy adults. It was found that the descending branch of the lateral circumflex femoral vessel was an ideal axial vessel. There are constant perforating branches of the myocutaneous artery or cutaneous branches from the intermuscular space to the anterolateral femoral skin. The area extends about 12 x 30 cm. Within the flap, the anterior branch of the anterolateral cutaneous nerve of the high is located. This flap has been widely used for free transplantation in China since 1983 with satisfactory results. 相似文献