Abstract
Using native gel electrophoresis, we demonstrate that both bovine brain hsc70 and recombinant rat hsc70 form a tightly associated complex with bovine S-carboxymethyl alpha-lactalbumin (CMLA). The formation of the complexes can be inhibited by an octapeptide (KLALSLHD). The recombinant C-terminal 30-kDa fragment also can be tightly associated with CMLA. Consequently, the 44-kDa ATPase domain of hsc70 plays a small role in the formation of the hsc70/CMLA. The N-terminal 60-kDa fragment of hsc70 cannot form a similar complex, despite the finding that the hydrolysis of ATP both by hsc70 and by the 60-kDa fragment can be stimulated by CMLA in a similar concentration-dependent manner with EC50 values of 15 microM. Moreover, the C-terminal 10-kDa fragment of hsc70 cannot tightly associate with CMLA, indicating that this fragment is necessary but not sufficient for the formation of the hsc70/CMLA complex.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphatases / chemistry
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Adenosine Triphosphatases / genetics
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Adenosine Triphosphatases / metabolism
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Amino Acid Sequence
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Animals
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Base Sequence
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Carrier Proteins / chemistry*
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Carrier Proteins / genetics
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Carrier Proteins / metabolism
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Cattle
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DNA Primers / genetics
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HSC70 Heat-Shock Proteins
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HSP70 Heat-Shock Proteins*
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In Vitro Techniques
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Lactalbumin / analogs & derivatives
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Lactalbumin / chemistry
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Lactalbumin / metabolism
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Macromolecular Substances
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Molecular Sequence Data
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Peptide Fragments / chemistry*
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Peptide Fragments / genetics
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Peptide Fragments / metabolism
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Protein Folding
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Rats
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
Substances
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Carrier Proteins
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DNA Primers
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HSC70 Heat-Shock Proteins
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HSP70 Heat-Shock Proteins
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Hspa8 protein, rat
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Macromolecular Substances
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Peptide Fragments
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Recombinant Proteins
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Lactalbumin
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Adenosine Triphosphatases