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21.
Trond P. Leren Kari Solberg Olaug K. Rødningen Oddveig Røsby Serena Tonstad Leiv Ose Kåre Berg 《Human genetics》1993,92(1):6-10
DNA from 40 unrelated familial hypercholesterolemia (FH) heterozygotes were subjected to analyses of single-strand conformation polymorphisms (SSCPs) of exon 10 of the low density lipoprotein receptor (LDLR) gene. Four different SSCP patterns were observed. The underlying mutations were characterized by DNA sequencing. Three of the patterns represented the three genotypes of a recently described sense mutation in codon 450. A method based upon the polymerase chain reaction (PCR) was developed to analyze this mutation. The frequencies of the wild-type (G at nucleotide 1413) and mutant (A at nucleotide 1413) alleles were 0.56 and 0.44, respectively. The fourth pattern was found in only one FH heterozygote and was caused by heterozygosity at nucleotide 1469 (G/A). Nucleotide 1469 is the second base of codon 469Trp(TGG). The GA mutation changes this codon into the amber stop codon, and is referred to as FH469Stop. The mutant receptor consists of the amino terminal 468 amino acids. Because the truncated receptor has lost the membrane-spanning domain, it will not be anchored in the cell membrane. FH469Stop destroys an AvaII restriction site, and this characteristic was used to develop a PCR method to establish its frequency in Norwegian FH subjects. Two out of 204 (1%) unrelated FH heterozygotes possessed the mutation. 相似文献
22.
Fiorito Serena Collevecchio Chiara Epifano Francesco Genovese Salvatore Palumbo Lucia 《Phytochemistry Reviews》2023,22(1):73-84
Phytochemistry Reviews - Oxyprenylated secondary metabolites of plant, fungal, and microbial origin have emerged as biologically active natural compounds with a great potential for the next future.... 相似文献
23.
The laboratory rearing of Neodiprion sertifer (Geoffroy) on Pinus sylvestris L. plants grown in vases was successfully achieved on a continuous basis. Larvae were seen to emerge on average after 106 days from egg clusters being kept on plants held at a temperature of 15 ± 1°C and with a 10‐h photophase until emergence. These larvae were then transferred to plastic containers and kept at a temperature of 20 ± 1°C with a 12‐h photophase where, under optimum hygiene conditions and being fed fresh pine branches, they completed their development on average in 30.6 days. Adults began emerging from the cocoons after about 30 days, continuing to do so for at least 7 months. Under these conditions the insect completes its life cycle in 179 days, thus permitting to obtain two generations a year in the laboratory. This staggered adult emergence pattern makes specimens available at all stages of development for experimental purposes throughout most of the year. 相似文献
24.
F. Bossa F. Martini D. Barra C.Borri Voltattorni A. Minelli C. Turano 《Biochemical and biophysical research communications》1977,78(1):177-184
The amino acid sequence of the coenzyme-binding site of DOPA-decarboxylase from pig kidney has been determined. A sample of enzyme was reduced with NABH4, aminoethylated and then digested with chymotrypsin. A single phosphopyridoxyl peptide was isolated and its sequence proved to be: Asn-Phe-Asn-Pro-His-Lys(Pxy)-Trp. Sequence homologies at the active site of various pyridoxalphosphate enzymes, and particularly of the bacterial decarboxylase, are discussed, with some emphasis on the constant presence of a histidine residue adjacent to the phosphopyridoxyl-lysine. 相似文献
25.
Summary
In vivo observations ofNicotiana glauca ×Nicotiana langsdorffii hybrid callus cells cultured on hanging-drop slides show a continuous pulsating movement of nucleoli containing vesicles from the nucleus into the cytoplasm and the occasional release of the nucleoli into the cytoplasmic stream. The phenomenon is discussed in relation to similar findings in other plant materials, particularly in critical phases of development.Contribution No. 151 from the Laboratorio di Mutagenesi e Differenziamento, Consiglio Nazionale delle Ricerche (C.N.R.), Pisa, Italy. Investigation supported by Consiglio Nazionale delle Ricerche (C.N.R.) under the programme Biology of Reproduction. 相似文献
26.
Questioning of reported evidence for guanosine tetraphosphate synthesis in a ribosome system from mouse embryos. 总被引:2,自引:0,他引:2
In 1974, Irr, Kaulenas and Unsworth reported that ppGpp is synthesized by cytosolic ribosomes from mouse embryos and proposed a role for ppGpp in the process of differentiation. This proposal is being challenged because ribosomes of mouse embryos from various stages of development and of mouse embryoid bodies were completely inactive in ppGpp formation. 相似文献
27.
Cloning and expression of human ciliary neurotrophic factor 总被引:1,自引:0,他引:1
A Negro E Tolosano S D Skaper I Martini L Callegaro L Silengo F Fiorini F Altruda 《European journal of biochemistry》1991,201(1):289-294
Ciliary neurotrophic factor (CNTF) is a survival factor for avian ciliary ganglion neurons and a variety of other neuronal cell types in vitro. We report here the cloning of the entire genomic sequence encoding human CNTF and its primary structure. Biologically active CNTF has been expressed in Chinese hamster ovary cells from a human genomic DNA clone. Human CNTF has no significant sequence similarity to any previously reported protein, although approximately 84% similarity exists compared with rat and rabbit CNTF. The lack of both an N-terminal signal sequence and consensus sequences for glycosylation or hydrophobic regions, and the fact that active CNTF is expressed but not released into the culture medium of transfected cells, argue in favour of human CNTF as a cytosolic protein. These data provide a basis for understanding the role of CNTF in nervous system physiology and pathology. 相似文献
28.
Vittoria Nuti Ronchi Lucia Giorgetti Mariagrazia Tonelli Guido Martini 《Plant Cell, Tissue and Organ Culture》1992,30(2):107-114
Cytological analysis of different carrot cell lines in culture has shown various cytogenetic anomalies generating new levels of ploidy and novel chromosome numbers. Polyploidy may be considered a reservoir of variability that can be released in the form of distinct new segregants of different ploidy. Mechanisms alternative to mitosis (reductional grouping, prophase chromosome reduction) operate from a polyploid state (possibly reached by means of endopolyploidy, endomitosis, nuclear fusion, or restitution nuclei) to generate new levels of ploidy and novel chromosome numbers necessary for selection to operate in vitro. The segregational phenomena require chromosome recognition in haploid set complements and abnormal behaviour of mitoses; the resulting chromosome variability suggests that chromosomes are arranged, in the resting nuclei, in an orderly and predictable manner.The knowledge of the molecular events governing these mechanisms, and how to control them, would be of great help for future applications of plant cell culture. 相似文献
29.
30.
Douglas L. Currell Bernice Law Michael Stevens Paul Murata Carmela Ioppolo Filippo Martini 《Biochemical and biophysical research communications》1981,102(1):348-354
Human hemoglobin reacts with 4-Isothiocyanatobenzene sulfonic acid at the four amino groups of the N-terminal valines. The modified protein shows a decreased oxygen affinity over a wide pH range, a reduced alkaline Bohr effect, decreased co-operativity, and a reduced effect of inositol hexasulfate on the oxygen affinity. 相似文献