Kallidin

Bradykinin is a nonapeptide enzymatically produced from kallidin in the blood, where it is a potent agent of arteriolar dilation and increased capillary permeability. 

Bradykinin Kallidin (lysyl-bradykinin) desArg9-bradykinin desAig10-kallidin (Lys°, desArg9-bradykinin) T-kinin (Ile-Ser-bradykinin)... 

In humans as well as in other but not all mammalian species, kininogens are modified by posttranslational hydroxylation of a single proline residue of their kinin sequence, i.e. position 3 in bradykinin or position 4 in kallidin. Hydroxylation appears not to affect the specificity, affinity or intrinsic efficacy of the kinins. 

L-kininogen Tissue kallikrein kallidin (KRPPGFSPFR) B2 receptor... 

KRPPGFSPF) Angiotensin converting enzyme (ACE) kallidin 1-6 (KRPPGF) Inactive... 

Kainate Receptor Kallidin, Lysyl-Bradykinin Kallikrein KCNQ-Channels KCOs... 

KDHRF A homologous restriction factor binds to C8 65KDHRF A homologous restriction factor, also known as C8 binding protein interferes with cell membrane pore-formation by C5b-C8 complex Kcat Catalytic constant a measure of the catalytic potential of an enzyme Ka Equilibrium dissociation constant kD Kilodalton Kd Dissociation constant KD Kallidin... 

E Wiinsch, H-G Heidrich, W Grassmann. Synthesis of Lys19-bradykinin and Lys210-kallidin. Chem Ber 97, 1818, 1964. 

Bradykinin, Angiotensine (verschiedene Arten des Typs I und II), Kallidin, Eledoisin. 

The kallikrein-kinin system is an enzymatic pathway giving rise to two predominant vasoactive peptides, kallidin and bradykinin. Kallikrein, the enzyme responsible for the formation of these peptides, exists in plasma and tissues. However, circulating levels of the end products, kalhdin and bradykinin, are quite low because the kalhkrein enzymes are present largely in inactive forms. In addition, the short half-life of these peptides (15 seconds) also contributes to low plasma levels. In general, the kinins produce relaxation of vascular smooth muscle and vasodilation. Bradykinin causes... 

The pathway for the formation and metabolism of kinins is shown in Figure 17-4. Three kinins have been identified in mammals bradykinin, lysylbradykinin (also known as kallidin), and methionyllysylbradykinin. Each contains bradykinin in its structure. 

Another kinin, Lys-bradykinin (also known as kallidin), is produced via the action of the tissue-kallikrein enzyme on LMWK. This enzyme is found in many tissues, either in the form of a precursor requiring activation or as an active enzyme. In contrast to plasma kallikrein, which preferentially acts upon HMWK, tissue kallikrein can release kallidin from either HMWK or LMWK. Through the action of aminopeptidases, kallidin can subsequently be converted directly into bradykinin. This enzyme is present in both the plasma and on the surface of epithelial cells. 

Nearly all cells express kinin receptors that mediate the activities of both bradykinin and kallidin. The activation of these G-protein coupled receptors causes relaxation of venular smooth muscle and hypotension, increased vascular permeability, contraction of smooth muscle of the gut and airway leading to increased airway resistance, stimulation of sensory neurons, alteration of ion secretion of epithelial cells, production of nitric oxide, release of cytokines from leukocytes, and the production of eicosanoids from various cell types [11,12]. Because of this broad spectrum of activity, kinins have been implicated as an important mediator in many pathophysiologies including pain, sepsis, asthma, rheumatoid arthritis, pancreatitis, and a wide variety of other inflammatory diseases. Moreover, a recent report demonstrated that bradykinin B2 receptors on the surface of human fibroblasts were upregulated three-fold beyond normal in patients with Alzheimer s disease, implicating bradykinin as a participant in the peripheral inflammatory processes associated with that disease [13]. 

In mucosal sheets from porcine ileum, the delta opioid agonist DPDPE inhibits saxitoxin-sensitive elevations in neurogenic ion transport evoked by histamine [142], tryptase-like enzymes [143], serotonin [144], kallidin [145], and type I hypersensitivity [142]. These effects of DPDPE are inhibited by naltrindole. In contrast, elevations in neurogenic ion transport occurring secondary to an immediate hypersensivity reaction in the guinea pig ileal mucosa are augmented by DPDPE, indicating that the neuromodulatory actions of opioids on active mucosal transport evoked by inflammation or anaphylaxis may depend on the species examined [146],... 

Muscle cells release kallikrein during inflammation causing formation of active kinin peptides (bradykinin and kallidin) from kininogen [65, 66]. Kinins are peptide hormones that produce vasodilation, increase capillary permeability, and cause pain and infiltration of neutrophils. There is a direct correlation between the amount of kinin in plasma or tissues and the degree of inflammation. Vascular dilation causes increased blood flow to infection [67, 68], Bik inhibits formation of kinins and vascular dilation by kallikrein, thereby inhibiting smooth muscle contraction [69-71],... 

Bradykinin 87 and kallidin (Lys-bradykinin-decapeptide), which are split off from the kininogen in the plasma by trypsin and kallikrein respectively (Fig. 10), hardly differ in their pharmacological activity. The most important effect of the kinins is a dilation of the peripheral vessels, which leads to an improved blood flow, in the kidneys for example, and therefore increases diuresis. By acting on the formation of angiotensin II, kinins can contribute to the regulation of blood pressure. Moreover, kinins cause a contraction of the bronchial muscle. 

Two different mixtures of peptides and alkaloids (qv) have been analyzed by ce/uv/ms using sims to determine whether this technique can detect trace impurities in mixtures (85). The first mixture consisted of two bioactive peptide analogues, which included Lys-bradykinin (kallidin) and Met-Lys-bradykinin. The presence of 0.1% Lys-bradykinin was detected by sim ce/ms but not by ce/uv at 0.1% level as it migrated from the capillary column prior to the main component, Met-Lys-bradykinin. The second mixture consisted of two antibacterial alkaloids, berberine and palmitine. The presence of 0.15% palmitine was detected by ce/uv and sim ce/ms at 0.15% level as it migrated from the capillary column, following the main component berberine. This technique can provide a complementary technique for trace components in such sample mixtures. 

Kallidin (E) is a decapeptide that serves as a vasodilator. The composition of E is Arg2 Gly Lys Phe2 Pro3 Ser. The C-terminal residue is Arg. Partial acid hydrolysis yields the following fragments ... 

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