Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.23 (MMP)
 4,246 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Earthworm coelomocytes exist in two forms, i.e., small (SC) and large (LC) cells, as demonstrated by velocity sedimentation, electron microscopy, and FCM. However, we know little concerning the functional activities of various, important organelles, such as mitochondria. In comparison with SC, LC from Eisenia foetida have a higher number of mitochondria, and, accordingly, showed a greater fluorescence intensity when mitochondrial mass was measured by nonyl acridine orange and FCM. To measure MMP we used both the lipophilic cationic probe JC-1 and Rh123. The intracellular localization of JC-1 in SC and LC was observed by fluorescence microscopy. Using JC-1, MMP was analyzed separately on SC and LC by FCM, and significant percentages of coelomocytes (> 95% of SC and about 90% of LC) displayed a high MMP. Adding 0.1 microM VAL caused most SC to depolarize, while this occurred in only a few LC. Rh123 gave different results: no effects of VAL were observed either in SC or in LC. In coelomocytes there may be several energy-independent Rh123-binding sites whose role must still be elucidated. On the whole, these data indicate that it is possible to analyze mitochondrial parameters by FCM in intact invertebrate coelomocytes, and that the type of cell and the probe used have a critical importance.
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PMID:Mitochondrial mass and membrane potential in coelomocytes from the earthworm Eisenia foetida: studies with fluorescent probes in single intact cells. 767 58

Membrane type 1-matrix metalloproteinase (MT1-MMP) is a zinc-dependent, membrane-associated endoproteinase of the metzincin family. The enzyme regulates extracellular matrix remodeling and is capable of cleaving a wide variety of transmembrane proteins. The enzymatic activity of MT1-MMP is regulated by endogenous inhibitors, the tissue inhibitor of metalloproteinases (TIMP). To date, four variants of mammalian TIMP have been identified. Whereas TIMP-2-4 are potent inhibitors against MT1-MMP, TIMP-1 displays negligible inhibitory activity against the enzyme. The rationale for such selectivity is hitherto unknown. Here we identify the surface epitopes that render TIMP-1 inactive against MT1-MMP. We show that TIMP-1 can be transformed into an active inhibitor against MT1-MMP by the mutation of a single residue, namely threonine 98 to leucine (T98L). The resultant mutant displayed inhibitory characteristics of a typical slow, tight binding inhibitor. The potency of the mutant could be further enhanced by the introduction of valine 4 to alanine (V4A) and proline 6 to valine (P6V) mutations. Indeed, the inhibitory profile of the triple mutant (V4A/P6V/T98L) is indistinguishable from those of other TIMPs. Our findings suggest that threonine 98 is critical in initiating MMP binding and complex stabilization. Our findings also provide a potential mechanistic explanation for MMP-TIMP selectivity.
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PMID:Unveiling the surface epitopes that render tissue inhibitor of metalloproteinase-1 inactive against membrane type 1-matrix metalloproteinase. 1286 73

A comparative study of infrared and Raman spectra of DL-valine DL-valinium picrate (DL-VVP) and DL-methionine DL-methioninium picrate (DL-MMP) at the room temperature in 4000-50 cm(-1) range helps to determine the effect of hydrogen bonds in these crystals. The existence of the zwitterion and the protonated form in both the crystals has been observed. In DL-MMP, the methionine and the methioninium residues form a dimer through a strong hydrogen bond between them in the crystal. The characteristic bands due to gem-methyl group are observed in the case of DL-VVP. Factor group analysis has been made and the numbers of vibrational modes have been calculated. The tentative assignments of the observed bands are given. The picrate group forms the anion in both the crystals and it is unaffected by the presence of the cations.
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PMID:Vibrational spectral analysis of DL-valine DL-valinium and DL-methionine DL-methioninium picrates. 1668 49