Effect of Point Mutations on the Kinetics and the Inhibition of Human Immunodeficiency Virus Type 1 Protease: Relationship to Drug Resistance
| Autor: | Yingzhang Lin, Ben M. Dunn, Raterman D, S. I. Foundling, Suvit Thaisrivongs, Lin Hong, Leelamanit W, Shah M, Lin X, Robert L. Heinrikson |
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| Rok vydání: | 1995 |
| Předmět: |
Models
Molecular medicine.medical_treatment Molecular Sequence Data Mutant Biology medicine.disease_cause Biochemistry Catalysis Substrate Specificity Motion Structure-Activity Relationship HIV Protease medicine Point Mutation Structure–activity relationship HIV Protease Inhibitor Amino Acid Sequence Enzyme kinetics DNA Primers chemistry.chemical_classification Mutation Protease Base Sequence Point mutation HIV Protease Inhibitors Hydrogen-Ion Concentration Protein Structure Tertiary Kinetics Enzyme chemistry Mutagenesis Site-Directed Peptides |
| Zdroj: | Biochemistry. 34:1143-1152 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi00004a007 |
| Popis: | Mutations of human immunodeficiency virus type 1 (HIV-1) protease at four positions, Val82, Asp30, Gly48, and Lys45 were analyzed for the resulting effects on kinetics and inhibition. In these mutants, Val82 was substituted separately by Asn, Glu, Ala, Ser, Asp, and Gln; Asp30 was individually substituted by Phe or Trp; Gly48 by His, Asp, and Tyr, respectively; and Lys45 by Glu. By examination of the inhibition of a single inhibitor, the differences in Ki values between the native and mutant enzymes can range from very large to insignificant even for the mutants with substitutions at the same position. By examination of a single mutant enzyme, the same broad range of Ki changes was observed for a group of inhibitors: Thus, how much the inhibition changes from the wild-type enzyme to a mutant is dependent on both the mutation and the inhibitor. The examination of Ki changes of inhibitors with closely related structures binding to Val82 mutants also reveals that the change of inhibition involves subsites in which Val82 is not in direct contact, indicating a considerable flexibility of the conformation of HIV protease. For the catalytic activities of the mutants, the kcat and Km values of many Val82 mutants and a Lys45 mutant are comparable to the native enzyme. Surprisingly, Gly48 mutations produce enzymes with catalytic efficiency superior to that of the wild-type enzyme by as much as 10-fold. Modeling of the structure of the mutants suggests that the high catalytic efficiency of some substrates is related to an increase of rigidity of the flap region of the mutants. The examination of the relative changes of inhibition and catalysis of mutants suggests that some of the Val82 and Gly48 mutants are potential resistance mutants. However, the resistance is specific with respect to individual inhibitors. |
| Databáze: | OpenAIRE |
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