Use of a Third Polymer as Ligand Carrier

The ligand can be bound to a third polymer chosen in such a way that it will be mainly concentrated in one phase. Alternatively, if it is carrying enough charged groups, it may be steered to one phase by using salts. The efficiency, measured as A log K/log Kl, equal to the apparent number of binding sites of the protein, has in several cases showed that the most effective polymer for carrying the ligand is neither of the two phase-forming polymers. The effect of a dye ligand, bound to various polymers, on the partitioning of lactate dehy-drogenase in a dextran-PEG system is presented in Table 4.

Table 4 The effect of ligand carrier on its efficiency in producing affinity partitioning

Ligand carrying polymer

A log Kldh

log Kl -polymer

napp = A log Kldh/log Kl -polymer

Ficoll

2.11

0.90

2.3

Hydroxypropylstarch

0.59

0.32

1.8

Poly(ethylene glycol)

2.23

1.50

1.5

Dextran (D.S. = 8.3)

2.31

1.60

1.4

Ethylhydroxyethyl cellulose

2.06

1.63

1.3

Lactate dehydrogenase (LDH) was partitioned in systems containing 7% (w/w) dextran 500, 5% w/w PEG 8000, 25 mM sodium phosphate buffer, pH 7.5, and Procion yellow HE-3G polymer of dye concentration of 42 ^M. Temperature, 22°C. (Reprinted from Johansson and Joelsson M (1984) Journal ofChromatography 411: 161-166. With permission from Elsevier Science.)

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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