Peptides listed

Apart from the economic figures, there also is a large variation in terms of molecular weight. The smallest amino acid molecule. Glycine, has a MW of 75, while the largest peptide listed in Table 3.1, Hirudin, has a MW of 7000. 

DBS and NLS stand for DNA binding signal and nuclear localization signal, respectively. Helper indicates that the transfection is efficient in the presence of additives for the cytosolic translocation. Chlo and lipo are chloroquine and cationic lipids, respectively. JTS-1 and HA are fusogenic peptides listed in Table 1. 

Matrix-assisted laser desorption-ionization ionizes molecules with molecular masses of 100-1,000,000 Da for analysis by MS and provides high sensitivity, high throughput, and simplicity of operation. MALDI combined with enzymatic reactions and protein chemistry can provide very useful information on molecular masses, peptide maps, and primary structure.15 MALDI-TOF MS can quickly and accurately determine unfractionated mixtures at concentrations below 100 fmol per liter. The obtained data are then calibrated with internal standards, monoisotopic masses are assigned for all prominent peaks, and the peptide list thus generated is used to identify the protein by using a suitable database.16... 

Table VII summarizes the conditions for chymotryptic hydrolysis of the proteins and peptides listed in Table VI. The parameters which would be expected to determine the rate of hydrolysis (apart from the nature of the bonds in the particular substrates) are temperature, pH, time of hydrolysis, and the molar ratio of chymotrypsin to substrate. All these factors often differ considerably for the substrates listed. Hydrolyses have been performed under conditions which vary from 2 to 24 hr, from pH 7.0 to 9.0, from 22° to 40°C, and at enzyme to substrate molar ratios between 1/360 to 1/21. It is not obvious how variations in pH and temperature affect the apparent specificity of chymotrypsin, but at low molar ratios of enzyme to substrate only the most susceptible bonds would be expected to be hydrolyzed. The lowest molar ratio was employed in the studies with ribonuclease. The only bonds of an unusual nature which were split were those formed by serine and histidine in the following sequences, -Thr-Ser. . . Ala-Ala- and -Lys-His. . . Ileu-Ileu-. Many of the unusual splits listed in Table VI were observed in equine or human cytochrome c and in oxidized papain. Each of these substrates was digested for long periods of time and at high ratios of enzyme to substrate under conditions which would be expected to split bonds that are usually resistant to hydrolysis.

As discussed in section 2.2., N-terminal extensions of the active site portion of the gastrin molecule leads to a remarkable stabilization of its potential bioactive conformation with concomitant increase of hormonal potency. This aspect has been analyzed in the case of CCK too, by using the series of peptides listed in table 2 (64). CD measurements revealed that N-terminal extensions of the CCK nv-lecule in sequence mode are affecting only marginally the conformational st s of the bioactive core. As expected from what was known for gastrin, the CD... 

The peptides listed here are not associated with marked increases in gastrointestinal motility. Bethanechol, a muscarinic choUnoceptor agonist, is an effective stimulant of the gut. The answer is (B). 

Step 3. Peptide listing and comparison It takes the list of peptides identified by parent mass in step two and compares the theoretical fragment masses of these peptides to the experimentally derived fragment spectra. 

A typical approach to HX-MS involves creating the peptide list from data-dependent LC-MS/MS runs applied to a nondeuterated protein digest and searching the data against the protein sequence with proteomics-grade search engines such as Mascot or XITandem (see Eigure 3.1). It is quite effective to iterate such experiments a few times to maximize the list of identifiable peptides, because the... 

In the last three peptides listed in table 3, the angles around the carbonyl carbon atom are in good agreement. They are selected as the most probable values. It is interesting to note that they differ significantly from the angles found in iV-acetylglycine, which contains only one amino-acid residue. 

Software special DOS-PC computer programs for the generation of peptide lists and pipetting protocols are included in the synthesis kit and the operation software of the ASP222... 

Number the spot positions on the membranes with a pencil according to the peptide list for manual synthesis and place in separate reaction troughs. Alternatively, fix membranes on the platform of the ASP222. 

Clicking on a protein accession number from the list brings up further information (see Fig. 5), including the matched peptides, listed and mapped onto the protein sequence, as well as the percentage of sequence coverage and any unmatched masses. There will almost inevitably be some unmatched masses they can... 

We have examined the inhibitory activity of the peptides listed in Table V in order to estimate their binding affinity, since the inhibition constant is identical to the dissociation constant of the enzyme-inhibitor complex. The results listed indicate that the binding affinity of the inhibitors is contributed mainly by the short segment on the carboxyl-terminal side of the tetradecapeptide Little, if any, affinity was exhibited by angiotensin I and II which represent the amino-terminal segment of the substrate molecule. 

An interesting series of small peptides is represented by members such as Ala-Phe-NH2, His-Phe-NH2, Phe-Phe-NH2, and Phe-Phe. These peptides were all cleaved by cathepsin D preparations at purities of 50-100 units/mg protein, but when the purity rose to 150-200 units/mg these activities were lost. This digestion was obviously due to an impurity, possibly an aminopeptidase contaminant. The odd feature was that cleavage of these peptides was completely blocked by the addition of pepstatin or by the enzyme preparation s reaction with diazoacetylnorleucine methyl ester in the presence of cupric ions. These treatments also abolished all activity against the peptides listed in Table I. It must be concluded that the peptidase impurity had all the characteristics of a carboxyl type of enzyme. Possibly, some of the multiple forms of cathepsin D had a broader specificity than others, and these were lost as purification progressed. 

GaAs( 100) is chosen as a reference substrate, because the peptides listed in Table 14.1 bind comparatively well to this substrate. The cPAC values for the peptides discussed here in more detail are also given in Table 14.1. 

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