CCL

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001-es BibID:BIBFORM015742
Első szerző:Barta Judit (kardiológus)
Cím:Calpain-1-sensitive myofibrillar proteins of the human myocardium / Barta Judit, Tóth Attila, Édes István, Vaszily Miklós, Papp Gy. Julius, Varró András, Papp Zoltán
Dátum:2005
Megjegyzések:Calpain-1 is a ubiquitous intracellular Ca2+-activated protease, which has been implicated in the pathogenesis of reversible myocardial depression (i.e. myocardial stunning) that follows ischemia and reperfusion via myofibrillar protein degradation. However, the target proteins of this degradative process in the human myocardium have not yet been identified. In order to compare the levels of Calpain-1 susceptibility within a set of human myofibrillar proteins (titin, alpha-fodrin, desmin, troponin T (cTnT), troponin I (cTnI) and alpha-actinin), crude left ventricular tissue homogenates were incubated for 0.5, 15, 30, 60 or 120 min in the presence of Calpain-1 (1 U or 5 U). Differences in the kinetics and extents of protein degradation were subsequently evaluated by using silver-stained SDS-polyacrylamide gels and Western immunoblot analyses. These assays revealed myofibrillar proteins with high (titin and alpha-fodrin), moderate (desmin and cTnT), or low (cTnI and alpha-actinin) relative Calpain-1 susceptibilities. The level of phosphorylation of cTnI did not explain its relatively low Calpain-1 susceptibility. Moreover, the molecular mass distributions of the truncated alpha-fodrin, desmin and cTnI fragments resulting from Ca2+-dependent autoproteolysis exhibited marked similarities with those of their Calpain-1-clipped products. These in vitro results shed light on a number of structural (titin, alpha-fodrin, desmin and alpha-actinin) and regulatory (cTnT and cTnI) proteins within the contractile apparatus as potential targets of Calpain-1. Their degradation may contribute to the development of postischemic stunning in the human myocardium.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
calpain
desmin
stunning
titin
troponin I
troponin T
Megjelenés:Molecular and Cellular Biochemistry. - 278 : 1-2 (2005), p. 1-8. -
További szerzők:Tóth Attila (1971-) (biológus) Édes István (1952-) (kardiológus) Vaszily Miklós (1949-) (szívsebész) Papp Gy. Julius (Szeged) Varró András (1954-) (farmakológus, klinikai farmakológus) Papp Zoltán (1965-) (kardiológus, élettanász)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM015741
Első szerző:Barta Judit (kardiológus)
Cím:Calpain-1-dependent degradation of troponin I mutants found in familial hypertrophic cardiomyopathy / Barta Judit, Tóth Attila, Jaquet Kornelia, Redlich Alexander, Édes István, Papp Zoltán
Dátum:2003
Megjegyzések:The mechanism by which mutations of the cardiac troponin I (cTnI) gene evoke familial hypertrophic cardiomyopathy (fHCM)is unknown. In this investigation the potential effects of three fHCM-related cTnI mutations on Calpain-1-induced cTnI degradation were tested, and a study was made of whether additional conformational changes due to troponin complex formation and protein kinase A-induced phosphorylation affect the intensity of cTnI proteolysis. Purified recombinant wild-type cTnI and three of its fHCM-related missense mutants (R145G, G203S and K206Q), alone or in the troponin complex (i.e. together with troponin C and troponin T), in the non-phosphorylated or protein kinase A-bisphosphorylated forms were proteolyzed invitro in the presence of Calpain-1 (0.05?2.5 U) at 30?C. Following incubation with Calpain-1 for 0.5, 30, 60 or 120 min, the extent of protein degradation was evaluated through the use of Western immunoblotting and densitometry. The results indicated that both the wild-type and the mutant cTnI molecules were susceptible to Calpain-1. However, the degradation of the cTnI molecules in the troponin complex was less intense than that of the non-complexed forms. Moreover, phosphorylation by protein kinase A conferred effective protection against cTnI proteolysis. The data suggested that mutations in the central inhibitory domain (R145G) and in the C-terminal region (G203S and K206Q) of cTnI do not affect its Calpain-1-mediated degradation, or the phosphorylation-induced protection against proteolysis.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
hypertrophic cardiomyopathy
calpain
troponin I
mutation
Megjelenés:Molecular and Cellular Biochemistry. - 251 : 1-2 (2003), p. 83-88. -
További szerzők:Tóth Attila (1971-) (biológus) Jaquet, Kornelia Redlich, Alexander Édes István (1952-) (kardiológus) Papp Zoltán (1965-) (kardiológus, élettanász)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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3.

001-es BibID:BIBFORM068537
Első szerző:Kovács Árpád (kardiológus)
Cím:Myosin heavy chain and cardiac troponin T damage is associated with impaired myofibrillar ATPase activity contributing to sarcomeric dysfunction in Ca2+-paradox rat hearts / Árpád Kovács, Judit Kalász, Enikő T. Pásztor, Attila Tóth, Zoltán Papp, Naranjan S. Dhalla, Judit Barta
Dátum:2017
ISSN:0300-8177
Megjegyzések:This study aimed to explore the potential contribution of myofibrils to contractile dysfunction in Ca2+-paradox hearts. Isolated rat hearts were perfused with Krebs?Henseleit solution (Control), followed by Ca2+-depletion, and then Ca2+-repletion after Ca2+-depletion (Ca2+-paradox) by Langendorff method. During heart perfusion left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of pressure development (+?dP/dt), and pressure decay (-dP/dt) were registered. Control LVDP (127.4???6.1 mmHg) was reduced during Ca2+-depletion (9.8???1.3 mmHg) and Ca2+-paradox (12.9???1.3 mmHg) with similar decline in +dP/dt and ?dP/dt. LVEDP was increased in both Ca2+-depletion and Ca2+-paradox. Compared to Control, myofibrillar Ca2+-stimulated ATPase activity was decreased in the Ca2+-depletion group (12.08???0.57 vs. 8.13???0.19 ?mol Pi/mg protein/h), besides unvarying Mg2+ ATPase activity, while upon Ca2+-paradox myofibrillar Ca2+-stimulated ATPase activity was decreased (12.08???0.57 vs. 8.40???0.22 ?mol Pi/mg protein/h), but Mg2+ ATPase activity was increased (3.20???0.25 vs. 7.21???0.36 ?mol Pi/mg protein/h). In force measurements of isolated cardiomyocytes at saturating [Ca2+], Ca2+-depleted cells had lower rate constant of force redevelopment (ktr,max, 3.85???0.21) and unchanged active tension, while those in Ca2+-paradox produced lower active tension (12.12???3.19 kN/m2) and ktr,max (3.21???23) than cells of Control group (25.07???3.51 and 4.61???22 kN/m2, respectively). In biochemical assays, ?-myosin heavy chain and cardiac troponin T presented progressive degradation during Ca2+-depletion and Ca2+-paradox. Our results suggest that contractile impairment in Ca2+-paradox partially resides in deranged sarcomeric function and compromised myofibrillar ATPase activity as a result of myofilament protein degradation, such as ?-myosin heavy chain and cardiac troponin T. Impaired relaxation seen in Ca2+-paradoxical hearts is apparently not related to titin, rather explained by the altered myofibrillar ATPase activity.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Calcium paradox
Myofibrillar ATPase activity
Isolated cardiomyocytes
Myofilament protein degradation
Megjelenés:Molecular and Cellular Biochemistry 403 : 1-2 (2017), p. 57-68. -
További szerzők:Kalász Judit (1986-) (molekuláris biológus) Pásztorné Tóth Enikő (1966-) (laboratóriumi analitikus) Tóth Attila (1971-) (biológus) Papp Zoltán (1965-) (kardiológus, élettanász) Dhalla, Naranjan S. Barta Judit (1975-) (kardiológus)
Pályázati támogatás:GINOP-2.3.2-15-2016-00043
GINOP
K116940
OTKA
K109083
OTKA
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