共查询到20条相似文献,搜索用时 46 毫秒
1.
S V Wu P Chew F J Ho J H Walsh H Wong T D Lee M T Davis J E Shively J R Reeve 《Biochemical and biophysical research communications》1989,161(1):69-74
A peptide identical in structure to the carboxyl-terminal flanking nonapeptide of rat progastrin, predicted by cDNA sequence, was synthesized. The synthetic peptide was used for production of a rabbit antiserum. This antiserum was used to develop a radioimmunoassay specific for rat carboxyl terminal flanking peptide. This assay was used to monitor the purification of immunoreactivity from rat antral extracts. Gel permeation, anion exchange and reverse phase chromatography steps resulted in a single absorbance peak associated with the carboxyl terminal flanking peptide immunoreactivity. The purified peptide eluted in the same position as the synthetic peptide during all three types of chromatography. This material was shown to be identical in mass to Ser-Ala-Glu-Glu-Glu-Asp-Gln-Tyr-Asn, the predicted sequence of the carboxyl terminal nonapeptide of rat progastrin. 相似文献
2.
Bovine heart troponin T was hydrolyzed at the single cysteine residue. This procedure resulted in two peptides--a short N-terminal peptide (40-50 amino acid residues) and a long C-terminal peptide (240 amino acid residues). The C-terminal peptide was purified to homogeneity by ion-exchange chromatography; its properties were compared to those of intact troponin T. Data from circular dichroism spectroscopy suggest that the short N-terminal peptide cleavage was unaccompanied by any conspicuous changes in the secondary structure of the large C-terminal peptide of troponin T. Unlike intact troponin T, its C-terminal peptide can interact with troponin C in the presence of Ca2+. Data from affinity chromatography demonstrated that troponin I and tropomyosin more strongly interacted with native troponin T than with its C-terminal peptide. It is concluded that the short N-terminal peptide (40-50 residues) plays an essential role in cardiac troponin T interaction with troponin and tropomyosin components. 相似文献
3.
Davies A Kalb S Liang B Aldrich CJ Lemonnier FA Jiang H Cotter R Soloski MJ 《Journal of immunology (Baltimore, Md. : 1950)》2003,170(10):5027-5033
The MHC class Ib molecule Qa-1 binds specifically and predominantly to a single 9-aa peptide (AMAPRTLLL) derived from the leader sequence of many MHC class Ia proteins. This peptide is referred to as Qdm. In this study, we report the isolation and sequencing of a heat shock protein 60-derived peptide (GMKFDRGYI) from Qa-1. This peptide is the dominant peptide bound to Qa-1 in the absence of Qdm. A Qa-1-restricted CTL clone recognizes this heat shock protein 60 peptide, further verifying that it binds to Qa-1 and a peptide from the homologous Salmonella typhimurium protein GroEL (GMQFDRGYL). These observations have implications for how Qa-1 can influence NK cell and T cell effector function via the TCR and CD94/NKG2 family members, and how this effect can change under conditions that cause the peptides bound to Qa-1 to change. 相似文献
4.
T Uesaka T Ikeda I Kubota Y Muneoka M Ando 《Biochemical and biophysical research communications》1991,180(2):828-832
A novel peptide, H-Gly-Phe-Trp-Asn-Lys-OH, was isolated from eel guts. This peptide, termed eel intestinal pentapeptide (EIPP), enhanced the frequency of the spontaneous contractions and increased the basal tone of the circular muscle of the esophagogastric junction. Furthermore, EIPP enhanced the spontaneous contractions of the longitudinal muscle strips of the gut and stomach, and of the circular muscle of the gastro-intestinal junction. The peptide may be a physiological regulatory peptide in the gastro-intestinal tract of the eel. 相似文献
5.
J A Martial 《Hormone research》1989,32(1-3):9-12
This very short review aims at analyzing the current biochemical view of the molecular steps involved in the peptide hormone synthesis, going from the gene to the final active peptide. 相似文献
6.
Isolation of maxadilan, a potent vasodilatory peptide from the salivary glands of the sand fly Lutzomyia longipalpis 总被引:3,自引:0,他引:3
E A Lerner J M Ribeiro R J Nelson M R Lerner 《The Journal of biological chemistry》1991,266(17):11234-11236
Blood feeding by the sand fly Lutzomyia longipalpis is aided by the presence of a vasodilator in its salivary glands. This novel vasodilator has been isolated by reversed-phase high-performance liquid chromatography. Ten nanograms of the vasodilator are present in the extract of a pair of sand fly salivary glands. It has 500 times the vasodilatory activity of calcitonin gene-related peptide, previously the most potent vasodilator peptide known. This novel peptide is thus called maxadilan. 相似文献
7.
Bland FA Lemberg MK McMichael AJ Martoglio B Braud VM 《The Journal of biological chemistry》2003,278(36):33747-33752
The nonclassical major histocompatibility complex class I molecule HLA-E acts as a ligand for CD94/NKG2 receptors on the surface of natural killer cells and a subset of T cells. HLA-E presents closely related nonameric peptide epitopes derived from the highly conserved signal sequences of classical major histocompatibility complex class I molecules as well as HLA-G. Their generation requires cleavage of the signal sequence by signal peptidase followed by the intramembrane-cleaving aspartic protease, signal peptide peptidase. In this study, we have assessed the subsequent proteolytic requirements leading to generation of the nonameric HLA-E peptide epitopes. We show that proteasome activity is required for further processing of the peptide generated by signal peptide peptidase. This constitutes the first example of capture of a naturally derived short peptide by the proteasome, producing a class I peptide ligand. 相似文献
8.
The ribosomal peptidyl transferase center is responsible for two fundamental reactions, peptide bond formation and nascent peptide release, during the elongation and termination phases of protein synthesis, respectively. We used in vitro genetics to investigate the functional importance of conserved 23S rRNA nucleotides located in the peptidyl transferase active site for transpeptidation and peptidyl-tRNA hydrolysis. While mutations at A2451, U2585, and C2063 (E. coli numbering) did not significantly affect either of the reactions, substitution of A2602 with C or its deletion abolished the ribosome ability to promote peptide release but had little effect on transpeptidation. This indicates that the mechanism of peptide release is distinct from that of peptide bond formation, with A2602 playing a critical role in peptide release during translation termination. 相似文献
9.
Primary structures of the bombesin-like neuropeptides in frog brain show that bombesin is not the amphibian gastrin-releasing peptide 总被引:1,自引:0,他引:1
J M Conlon F O'Harte H Vaudry 《Biochemical and biophysical research communications》1991,178(2):526-530
Peptides displaying gastrin-releasing peptide/bombesin-like immunoreactivity were isolated in pure form from an extract of the brain of the European green frog, Rana ridibunda. The primary structure of the more abundant peptide was established as: Gly-Ser-His-Trp-Ala-Val-Gly-His-Leu-Met. NH2. This sequence shows one substitution (Ser for Asn) compared with mammalian gastrin-releasing peptide (18-27) (neuromedin C). The extract also contained gastrin-releasing peptide but bombesin was absent. The data indicate that bombesin is not the amphibian counterpart of gastrin-releasing peptide. 相似文献
10.
Expediting the Fmoc solid phase synthesis of long peptides through the application of dimethyloxazolidine dipeptides. 总被引:2,自引:0,他引:2
This paper describes the step-wise Fmoc solid phase synthesis of a 95-residue peptide related to FAS death domain. Attempts to prepare this peptide employing conventional amino acid building blocks failed. However, by the judicious use of dimethyloxazolidine dipeptides of serine and threonine, the peptide could be readily prepared in remarkable purity by applying single 1 h coupling reactions. 相似文献
11.
There is considerable interest in the structure of the denatured state and in the role local interactions play in protein stability and protein folding. Studies of peptide fragments provide one method to assess local conformational preferences which may be present in the denatured state under native-like conditions. A set of peptides corresponding to the individual elements of secondary structure derived from the N-terminal domain of the ribosomal protein L9 have been synthesized. This small 56 residue protein adopts a mixed alpha-beta topology and has been shown to fold rapidly in an apparent two-state fashion. The conformational preferences of each peptide have been analyzed by proton nuclear magnetic resonance spectroscopy and circular dichroism spectroscopy. Peptides corresponding to each of the three beta-stands and to the first alpha-helix are unstructured as judged by CD and NMR. In contrast, a peptide corresponding to the C-terminal helix is remarkably structured. This 17 residue peptide is 53 % helical at pH 5.4, 4 degrees C. Two-dimensional NMR studies demonstrate that the helical structure is distributed approximately uniformly throughout the peptide, although there is some evidence for fraying at the C terminus. Detailed analysis of the NMR spectra indicate that the helix is stabilized, in part, by a native N-capping interaction involving Thr40. A mutant peptide which lacks Thr40 is only 32 % helical. pH and ionic strength-dependent studies suggested that charge charge interactions make only a modest net contribution to the stability of the peptide. The protein contains a trans proline peptide bond located at the first position of the C-terminal helix. NMR analysis of the helical peptide and of a smaller peptide containing the proline residue indicates that only a small amount of cis proline isomer (8 %) is likely to be populated in the unfolded state. 相似文献
12.
Identification of a prothoracicostatic peptide in the larval brain of the silkworm, Bombyx mori. 总被引:4,自引:0,他引:4
Y J Hua Y Tanaka K Nakamura M Sakakibara S Nagata H Kataoka 《The Journal of biological chemistry》1999,274(44):31169-31173
Prothoracicotropic hormone (PTTH) stimulates ecdysteroid biosynthesis in the prothoracic gland (PG) of insects. A peptide inhibiting ecdysteroid biosynthesis in the PG was isolated from the extracts of 2,000 larval brains of the silkworm, Bombyx mori, using a protocol that included four reversed-phase high performance liquid chromatography procedures. The primary structure of this prothoracicostatic peptide (Bom-PTSP) was determined to be H-Ala-Trp-Gln-Asp-Leu-Asn-Ser-Ala-Trp-NH(2). This neuropeptide has the same sequence as Mas-MIP-I, a myoinhibitory peptide previously isolated from the ventral nerve cord of the tobacco hornworm, Manduca sexta, and is highly homologous with the N-terminal portion of vertebrate peptides of the galanin family. This peptide inhibited PTTH-stimulated ecdysteroidogenesis in the PG at both the spinning and feeding stages, which indicates that Bom-PTSP interferes with PTTH-stimulated ecdysteroidogenesis. 相似文献
13.
The isolation of a brain peptide identical to the intestinal peptide PHI (peptide HI) is described. The peptide was isolated from porcine brain extract using a chemical assay method based on its C-terminal isoleucine amide structure. The complete amino acid sequence of the peptide was found to be: His-Ala-Asp-Gly-Val-Phe-Thr-Ser-Asp-Phe-Ser-Arg-Leu-Leu-Gly-Gln-Leu-Ser-Ala- Lys-Lys-Tyr-Leu-Glu-Ser-Leu-Ile-NH2. This sequence is identical to the intestinal peptide thus demonstrating PHI to be a brain-gut peptide. The role of PHI in the central nervous system as a neurotransmitter or neuromodulator is discussed. 相似文献
14.
Alamethicin is a channel-forming peptide antibiotic that produces a highly voltage-dependent conductance in planar bilayers. To provide insight into the mechanisms for its voltage dependence, the dynamics of the peptide were examined in solution using nuclear magnetic resonance. Natural-abundance 13C spin-lattice relaxation rates and 13C-1H nuclear Overhauser effects of alamethicin were measured at two magnetic field strengths in methanol. This information was interpreted using a model-free approach to obtain values for the overall correlation times as well as the rates and amplitudes of the internal motions of the peptide. The picosecond, internal motions of alamethicin are highly restricted along the peptide backbone and indicate that it behaves as a rigid helical rod in solution. The side chain carbons exhibit increased segmental motion as their distance from the peptide backbone is increased; however, these motions are not unrestricted. Methyl group dynamics are also consistent with the restricted motions observed for the backbone carbons. There is no evidence from these dynamics measurements for a hinged motion of the peptide about proline-14. Alamethicin appears to be slightly less structured in methanol than in the membrane; as a result, alamethicin is also expected to behave as a rigid helix in the membrane. This suggests that the gating of this peptide involves changes in the orientation of the entire helix, rather than the movement of a segment of the peptide backbone. 相似文献
15.
Y D Karkhanis D J Carlo S W Brostoff E H Eylar 《The Journal of biological chemistry》1975,250(5):1718-1722
A 17-residue peptide (Peptide Y) was isolated from the COOH-terminal end of the basic protein of bovine myelin by peptic digestion. This peptide induced experimental allergic encephalomyelitis in the rhesus monkey. Treatment of Peptide Y with cyanogen bromide released three amino acids from the COOH-terminal end and resulted in a tetradecapeptide (Peptide M) which was also encephalitogenic in the rhesus monkey. The sequence of Peptide M is: Phe-Lys-LEU-Gly-Gly-Arg-Asp-Ser-Arg-Ser-Gly-Ser-Pro-Met. Thus a major disease-inducing site active in the rhesus monkey is contained within a 14-residue peptide localized near the COOH-terminal end of the protein. This peptide differs markedly in location and sequence from the 9-residue peptide shown to contain the encephalitogenic determinant for the guinea pig. 相似文献
16.
Identification of the DNA-binding domain of the FLP recombinase 总被引:6,自引:0,他引:6
We have subjected the FLP protein of the 2-micron plasmid to partial proteolysis by proteinase K and have found that FLP can be digested into two major proteinase K-resistant peptides of 21 and 13 kDa, respectively. The 21-kDa peptide contains a site-specific DNA-binding domain that binds to the FLP recognition target (FRT) site with an affinity similar to that observed for the native FLP protein. This peptide can induce DNA bending upon binding to a DNA fragment containing the FRT site, but the angle of the bend (approximately 24 degrees) is smaller in magnitude than that induced by the native FLP protein (60 degrees). The additional DNA bending induced by the interaction between two native FLP molecules bound to the FRT site is not observed with the 21-kDa DNA-binding peptide. Amino-terminal sequencing has been used to map this peptide to an internal region of FLP that begins at residue Leu-148. It is likely that the DNA-binding peptide includes the catalytic site of the FLP protein. 相似文献
17.
A peptide identified as the membrane-associated segment of NADPH-cytochrome P-450 reductase has been generated by steapsin protease treatment of vesicle-incorporated reductase and isolated by preparative gel electrophoresis. This peptide remains associated with vesicles when steapsin protease digests of vesicle-incorporated reductase were fractionated by Sepharose 4B chromatography, confirming its identity as the membrane-binding peptide. The molecular weight of the membrane-binding peptide was 6400 as determined by gel filtration in 8 M guanidine hydrochloride, and its amino acid content was not especially hydrophobic. The activity of reconstituted hydroxylation systems consisting of reductase, cytochrome P-446, and dilauroyl phosphatidylcholine was not inhibited by large molar excesses of purified membrane-binding peptide. Moreover, when purified reductase and cytochrome P-446 were added to liposomes which contained the membrane-binding peptide, it was determined that mixed function oxidase activity was reconstituted as effectively as when vesicles without the membrane-binding peptides were used. Similar results were obtained with reductase, cytochrome P-450, and detergent-solubilized liposomes (with or without the membrane-binding peptide). Thus, the membrane-binding peptide does not appear to interact with either of these two forms of the hemoprotein in a site-specific manner to prevent reconstitution of hydroxylation activity. 相似文献
18.
Structural requirement at the cleavage site for efficient processing of the lipoprotein secretory precursor of Escherichia coli 总被引:5,自引:0,他引:5
A phenotypically silent mutation in the signal peptide of the Escherichia coli outer membrane prolipoprotein was combined with other mutations in the mature lipoprotein structure. Under conditions where the individual mutations permit normal lipoprotein secretion, the prolipoprotein with both mutations was unable to be normally modified or processed. These results demonstrate that a given signal peptide is fully functional only if it is structurally compatible with the protein to be secreted. This structural compatibility between the signal peptide and the secretory protein is considered to be dependent on the secondary structure formed at or near the signal peptide cleavage site. 相似文献
19.
Richard M. Epand 《Bioscience reports》1986,6(7):647-653
Virus replication inhibitory peptide (carbobenzoxy-D-Phe-L-PheGly) was shown to be a potent specific inhibitor of the replication of paramyxovirus and myxovirus (Richardson, Scheid and Choppin (1980), Virology105, 205–222). This peptide inhibits the membrane fusing activity of a viral glycoprotein.Many agents which promote the formation of the hexagonal phase in membranes also accelerate membrane fusion. At a mole fraction of 0.1, viral replication inhibitory peptide can raise the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine by almost 10°. Two related peptides, carbobenzoxy-L-PheGly and carbobenzoxy-L-GlyPhe, are less potent in raising the bilayer to hexagonal phase transition temperature, with the latter peptide being the least effective of the three. This order of potency is the same as the order of potency in inhibiting viral replication. Substances which inhibit hexagonal phase formation of pure lipids may also inhibit membrane fusion.Abbreviations DEPE
dielaidoylphosphatidyethanolamine
- Z
carbobenzoxy
- DSC
differential scanning calorimetry
- VRIP
virus replication inhibitory peptide (Z-D-Phe-L-PheGly) 相似文献
20.
Moriarty LC Joannou CL van den Berg JJ Gorinsky B Evans RW 《FEMS microbiology letters》2004,239(2):295-299
This study investigated the antimicrobial activities of peptides derived from the N-terminal region of human lactoferrin, and examined the contributions of individual residues to the activity of the most potent peptide. Two regions of antimicrobial activity were identified, the first corresponding to a weakly active peptide, HLP-9, comprising residues 1-9, and a second corresponding to a more potent peptide, HLP-10, comprising residues 18-26 and containing the hexapeptide motif, FQWQRN. Inhibitory studies on peptides from the first region confirm the importance of tryptophan residues in enhancing and broadening peptide activity. Inhibitory studies with glycine-substituted homologues of the more potent peptide showed that F21/G and R25/G substitutions resulted in a major reduction or complete loss of activity, while increased peptide cationicity or flexibility had little effect. Our findings demonstrate that F21 and R25 are critical determinants of potency for HLP-10, and that the second aromatic residue may act synergistically with W23 in developing and enhancing the activity of this cationic peptide. 相似文献