Document 0576
 DOCN  M9550576
 TI    Stability of dimeric retroviral proteases.
 DT    9505
 AU    Darke PL; Biological Chemistry Department, Merck Research Laboratories,;
       West Point, Pennsylvania 19486.
 SO    Methods Enzymol. 1994;241:104-27. Unique Identifier : AIDSLINE
       MED/95157306
 AB    The determination of dimer stabilities for the retroviral proteases has
       proved more challenging than anticipated, but it is a tractable problem
       when careful attention is made to potential interferences. For
       investigations of retroviral proteases not yet characterized, the
       fundamentally rigorous sedimentation equilibrium and other biophysical
       techniques may yet provide useful Kd values. They are preferable to the
       indirect methods emphasized in this chapter but nevertheless should be
       coupled with basic considerations such as recovery of activity at the
       end of an experiment and the relevance of values obtained to other
       situations. In the likely event that nanomolar Kd values are encountered
       in new investigations, the assay techniques provide the most readily
       available methods for many laboratories. Because these methods are
       sensitive to anything that affects enzyme activity, the use of
       complementary methods to verify dimerization constants is imperative.
       Inactivating reactions not due to monomer formation should be explored,
       and the potential impact of those reactions on the constants being
       measured should be estimated. Most of the Kd and dimerization rate data
       available for retroviral proteases are obtained with the HIV-1 protease,
       with each investigator choosing methods and solvent conditions different
       from the others. The confusing diversity of results should be the
       impetus for a direct comparison of methods for the identification of the
       sources of differences. If more comprehensive and rigorous measures of
       the kinetics and thermodynamics of subunit aggregation are obtained,
       they might be coupled with the large volume of detailed structural data
       accumulating for this class of protein to provide insights into more
       general problems of protein-folding chemistry.
 DE    Aspartic Proteinases/ANTAGONISTS & INHIB/*CHEMISTRY  Binding Sites
       Fluorometry  HIV Protease/CHEMISTRY  HIV Protease
       Inhibitors/PHARMACOLOGY  HIV-1/ENZYMOLOGY  HIV-2/ENZYMOLOGY  Kinetics
       Molecular Weight  *Protein Conformation  Protein Denaturation  Protein
       Folding  Protein Hybridization  Retroviridae/*ENZYMOLOGY  Retroviridae
       Proteins/ANTAGONISTS & INHIB/*CHEMISTRY  JOURNAL ARTICLE  REVIEW
       REVIEW, TUTORIAL

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