Bradykinin fragment

Figure 5.1-2. Electropherogram of a mixture of bioactive peptides separated at pH 2.5. Peptides (1) reference (2) bradykinin (3) bradykinin fragment 1-5 (4)substance P (5) [arg]-vasopressin (6) luteinizing hormone releasing hormone (7) bombesin (8) leucine enkephalin (9) methionine enkephalin (10) oxytocin. (Reprinted from Ref. 13, with permission.)...

Brady kinin Bradykinin fragment Leucine encephalin... 

Peptide calibration standard II (Bruker Daltonics, Wissenbourg, France) angiotensin II, angiotensin I, substance P, bombesin, ACTH clip 1-17, ACTH clip 18-39, somatostatin 28, bradykinin fragment 1-7, renin substrate tetradecapeptide porcine. Covered mass range -700-3,200 Da. Store at -20°C. 

The substrate specificity of ACE is low. ACE cleaves a variety of pairs of amino acids from the carboxy-terminal part of several peptide substrates. The conversion of ANGI to ANGII and the degradation of bradykinin to inactive fragments are considered the most important functions of ACE. Both peptides have profound impact on the cardiovascular system and beyond. ACE is thus an important target for ACE inhibitors. These compounds are frequently and efficiently used in the treatment of hypertension and cardiac failure. 

Some agents are bifunctional, causing the release of histamine and recruiting leukocytes. Bifunctional mediators include bacterial peptides, endotoxins, DNA, C3a, C5a and bradykinin. Each of these substances can exert dual effects. This may either occur directly, as in the case of bacterial peptides and bradykinin causing chemotaxis and bronchial smooth muscle contraction, or indirectly, as endotoxin and DNA conversion of complement. C3a and C5a act indirectly as complement fragments to effect histamine release, which in turn contracts bronchial smooth muscle. However, both appear to act directly to effect chemotaxis with C5a, the more potent fragment. 

Inserted emitter, silver glue coated, PMMA chip ESI-ITMS BSA, fibrinopeptide A, osteocalcin fragment 7-19, bradykinin (all 10 pmol/jxL) Trypsin, off-chip Nil 814... 

In theory, Edman degradations could sequence a peptide of any length. In practice, however, the repeated cycles of degradation cause some internal hydrolysis of the peptide, with loss of sample and accumulation of by-products. After about 30 cycles of degradation, further accurate analysis becomes impossible. A small peptide such as bradykinin can be completely determined by Edman degradation, but larger proteins must be broken into smaller fragments (Section 24-9E) before they can be completely sequenced. 

The PSD MALDI spectrum of Des-Arg1 bradykinine, whose sequence is PPGF-SPFR. The starred peaks correspond to the loss of a 28 Da fragment. Reproduced (modified) from Rouse J.C., Yu W. and Martin S.A., J. Am. Mass Spectrom., 6, 822-835, 1996, with permission. 

Also, prolylendopeptidase inhibitory peptides (PEP) have been found in wines (Yanai et al. 2003). PEP may have a role in the degradation of biologically active peptides containing proline, such as oxytocin, vasopressin, substance P, bradykinin, neurotensins and angiotensins. Two inhibitory peptides have been isolated and characterized, Pep A (Val-Glu-Ile-Pro-Glu) and Pep B (Tyr, Pro, He, Pro, Phe). Both of them showed PEP inhibition, thereby suppressing the degradation of neuropeptides, vasopressin, substance P and fragments 8-13 of neurotensin, which are involved in memory and neural communication. 

Amfilochiadis A A, Papageorgiou P C, Kogan N, et al. (2004). Role of bradykinin B2-receptor in the sympathoadrenal effects of new pressor protein related to human blood coagulation factor XII fragment. 7. Hypertens. 22 1173-1181. 

Some examples of studies with MALDI and IMS include the use of MALDI to generate sodiated parent ions of a number of oligosaccharides without fragmentation and cationized forms of bradykinin. Cross sections of the ions were obtained and compared with predictions made by molecular mechanics or molecular dynamics calculations. Comparison of MALDI/IM/TOF-MS with MALDI/IM/MS analysis yielded results similar to that by nanoelectrospray MS. Dipeptides and biogenic amines were analyzed with a system that consisted of an atmospheric pressure MALDI source, an IMS, and an orthogonal TOF-MS, and sensitivity was improved when a localized CD source was added. ... 

Incubation of a protein fraction from blood plasma with trypsin gives rise to peptides with conspicuous biological effects. Pain, dilation of peripheral blood vessels, increased coronary flow and enhanced capillary permeability were observed on administration of these protein fragments [8]. In the early sixties the nonapeptide bradykinin and its precursors, kallidin and methionyl-kalUdin were isolated in pure form and their amino acid sequences determined soon after. 

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