A mammalian cell line was cultured for many generations in the presence of methotrexate, whose concentration in the culture medium was steadily increased. After maximum resistance to methotrexate had been achieved, the cells were transferred to drug-free medium for many more generations. At the beginning of the experiment, dihydrofolate reductase represented 0.1% of the soluble protein in the cell; at maximum resistance it was 10.0% and at the conclusion of the experiment, 1.5%. The qualitative terms the processes involved in generating maximum resistance needs to be described. Concept Introduction: Dihydrofolate reductase (DHFR) is asalvage pathway enzyme encoded by MDR gene involved in synthesis of dinucleotides like dTTP, dATP, dGTP used in DNA synthesis. Methotrexate (MTX) is a drug that inhibits DHFR. The qualitative terms associated with this process are decreased by the uptake of MTX by mammalian cells and DHFR gene amplification resulting in its increased production.

Question

Want to see the full answer?

Answer 1

Question

Chapter 23, Problem 16P

Interpretation Introduction

Interpretation:

A mammalian cell line was cultured for many generations in the presence of methotrexate, whose concentration in the culture medium was steadily increased. After maximum resistance to methotrexate had been achieved, the cells were transferred to drug-free medium for many more generations. At the beginning of the experiment, dihydrofolate reductase represented 0.1% of the soluble protein in the cell; at maximum resistance it was 10.0% and at the conclusion of the experiment, 1.5%. The qualitative terms the processes involved in generating maximum resistance needs to be described.

Concept Introduction:

Dihydrofolate reductase (DHFR) is asalvage pathway enzyme encoded by MDR gene involved in synthesis of dinucleotides like dTTP, dATP, dGTP used in DNA synthesis. Methotrexate (MTX) is a drug that inhibits DHFR.

The qualitative terms associated with this process are decreased by the uptake of MTX by mammalian cells and DHFR gene amplification resulting in its increased production.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

12. When glutamic acid is heated to 180°C., it loses a molecule of water to form a lactam. The bond that creates the lactam is an amide bond that forms between the amino nitrogen and the carbon of the side chain -COOH group. What is the most reasonable structure for this lactam? (NOTE: The structure of glutamic acid is shown in Question 1.) COOH COOH ا کچھ جو کچھ C D COOH B COOH E COOH

10. Which one of the following compounds is the major organic product of the series of reactions shown here? Ph A OH Ph B CO₂Et Br -H Ν ΚΑ CO₂Et 1. NaOEt 1. NaOH, H₂O 2. H3O+ 2. PhCH2CH2Br 3. heat NH2 Ph OH NH2 0 OH Ph OH NH2 Ph D NH2 E OH

1. What is the isoelectric point of glutamic acid? (Glutamic acid has pKa1 2.10, pKa2 4.07, pKaз 9.47) A) pH 2.1 D) pH 6.8 B) pH 3.1 C) pH 4.1 E) pH 9.5 HO NH2 Glutamic acid (shown without charges) OH