Disease relevance of Physalemin

• These data suggest that small-cell carcinoma of the lung contains a physalaemin-like peptide that has structural and biological homology to its amphibian counterpart [1].
• Comparative toxicity of amyloid beta-peptide in neuroblastoma cell lines: effects of albumin and physalaemin [2].

Psychiatry related information on Physalemin

• The present findings suggest that in adult rats central eledoisin and physalaemin exert a selective suppressive effect on drinking behavior without affecting feeding [3].

High impact information on Physalemin

• Substance P (SP), first identified by bioassay as early as 1931 but sequenced only in 1971, several years after the elucidation of the structure of eledoisin from molluscan tissues and of physalaemin from amphibian skin, may be considered as a prototype of the tachykinins [4].
• Both physalaemin and the tumor peptide produced a contractile response of isolated guinea pig ileum at threshold concentrations of approximately 100 to 150 picograms per milliliter [1].
• The disulfide bridge constraints have been designed on the basis of conformational studies on SP and physalaemin indicating an alpha-helical structure for the core of these two tachykinins (group I) and a folding of the C-terminal carboxamide towards the side chains of the glutamines 5 and 6 (group II) [5].
• These results indicate that dispersed acini from guinea pig pancreas possess a single class of receptors that interact with physalaemin, substance P, and eledoisin and that occupation of 45% of these receptors will cause a maximal biological response [6].
• Binding of 125I-labeled physalaemin was saturable, temperature-dependent, and reversible and reflected interaction of the labeled peptide with a single class of binding sites on the plasma membrane of pancreatic acinar cells [6].

Biological context of Physalemin

• We have prepared 125I-labeled physalaemin and have examined the kinetics, stoichiometry, and chemical specificity with which the labeled peptide binds to dispersed acini from guinea pig pancreas [6].
• The IC50 of SP in whole spinal cord was 0.46 nM as compared with 0.95, 60, and 150 nM for physalaemin, eledoisin, and kassinin [7].
• Intracerebroventricular injections of the naturally occurring tachykinins eledoisin, physalaemin and substance P elicit a powerful antidipsogenic effect in the rat, while in the pigeon they potently stimulate water intake [8].
• The relative potencies of SP and its fragments SP(2-11) and SP(4-11), as measured by their IC50, are in agreement with their rank order in the salivation assay, whereas physalaemin was found apparently weaker than expected [9].
• The antiserum was tested for cross-reaction with substance P, physalaemin, substance K and neuromedins B, C and K [10].

Anatomical context of Physalemin

• Our results indicated that the amphibian undecapeptide physalaemin inhibits the clonal and mass culture growth of SCLC cell lines at picomolar concentrations [11].
• The weak activity of eledoisin and physalaemin suggests that the substance P receptor, like that of the rat mast cell, is not of the classical types described for smooth muscle [12].
• The ultrastructural findings and the similar responses to methacholine and physalaemin suggest that autonomic neuropathy may be a factor in the abnormal response of the parotid gland to parasympathetic nerve stimulation [13].
• The action of SP on salivary glands, like physalaemin, resembled that of cholinergic stimulation [14].
• On the other hand, in rat cerebral cortex membranes BHE binding was inhibited by neuromedin K = kassinin = eledoisin greater than physalaemin greater than substance K greater than substance P indicating a definitive tachykinin E receptor site [15].

Associations of Physalemin with other chemical compounds

• Ranatensin, litorin, alytesin, and GRP, but not physalaemin, were as active as Tyr4-bombesin [16].
• 3. Exogenous perfusion of the mammalian tachykinins substance P, neurokinin A and neurokinin B and the non-mammalian tachykinins physalaemin, kassinin and eledoisin was used to determine the tachykinin receptor type mediating the plasma extravasation response [17].
• Three of the most potent antagonists were tested for specificity and found to block the smooth muscle contraction induced by SP, physalaemin, eledoisin and bombesin but not that induced by bradykinin, carbachol, 5-hydroxytryptamine, histamine, prostaglandins and vasopressin [18].
• 2. The contractile activity provoked by SP and physalaemin was inhibited by nifedipine (a Ca2+-entry blocker) and was abolished in Ca2+-free EGTA solution [19].
• Phenoxybenzamine did not affect the dose-response curves to SP, eledoisin-related peptide (ERP), kassinin, eledoisin or physalaemin, nor did it affect the responses to individual doses of DPDPDT or DT79 [20].

Gene context of Physalemin

• Of these SP analogues, [D-Arg1,D-Pro2,4,D-Phe7,D-His9]SP attenuated selectively the behavioural responses produced by NK-1 receptor agonists such as SP and physalaemin [21].
• These immunoconjugates, composed of IL-1 beta, IL-2, TNF-alpha, physalaemin, leukotriene B4, histamine, and bradykinin chemically linked to TNT-1, a murine monoclonal antibody that binds necrotic regions in tumors, have been tested for their effects on antibody uptake in vivo [22].
• The tachykinins neurokinin A and physalaemin stimulate murine thymocyte proliferation [23].
• The receptor for SP is particularly sensitive to SP and physalaemin and shows higher affinity for the whole natural peptides (SP, NKA) than for their C-terminal fragments [24].
• SP proved to be the most efficient IL-2 inducer, exerting its maximal effect at concentrations that were 4 to 5 orders of magnitude lower than the optimal stimulatory concentrations of physalaemin, NKA, or NKB [25].

Analytical, diagnostic and therapeutic context of Physalemin

• Thus, we developed a rapid physalaemin-specific radioimmunoassay that led to the initial discovery of a substance in mammalian tissues with an immunoreactivity resembling that of the original amphibian peptide [26].
• SK, kassinin and eledoisin were more potent than SP and physalaemin in increasing respiratory insufflation pressure [27].
• Equimolar amounts of the related peptides physalaemin and eledoisin-related peptide also caused analgesia, but the SP N-terminal fragment (1-9) was inactive [28].
• Bombesin, GRP, SP, physalaemin and eledoisin contracted the smooth muscle and potentiated the response to electrical stimulation [29].
• Substance P, P-octapeptide, physalaemin and eledoisin, and eledoisin related peptide were found to be potent miotics on these preparations, yielding ED50 values in the range of 8 to 95 nM and complete pupillary constriction in the range of 100 to 1000 nM [30].

References