Hello.

Thanks for your kind introduction.

I'm Xiaodong Ye from the University of Science and Technology of China.

It's my sixth time attending this AUC international conference.

From the beginning in Japan, I'm very glad to see all of you here.

First, I would like to thank Johannes for sending me the invitation letter so I could get my visa easily.

I would also like to thank the scientific organizing committee for giving me this chance to present our recent work about investigation of the

complexation between glycine and the block of polymer containing polyelectrolyte through analytical archi-centrification.

In early literature, Naismith was the first one to study the solvents using an analytical archi-centrification.

Specifically, using a model E AUC equipped with a Schlieren optical detector.

The results show that the extract protein contains at least four components with sedimentation coefficient of 2S, 7S, 11S, and 15S.

Note that sedimentation constant was still used at that time.

This figure shows our recent AUC characterization of the solvents protein at different purification steps.

The 11S molecule is a predominant component.

It is a hexamer composed with two trimer, each trimer comprising three subunits.

Each subunit is made up of an acidic peptide and an acidic peptide connected by a disulfide bond.

The 15S protein is a minor component.

We have previously characterized this fraction in detail by AUC and TN method,

demonstrating that this protein is formed by two 11S molecules.

Solvents proteins contain all amino acids for humans and have excellent gelling and emulsification properties.

The interaction between the solvents protein and the polyelectrolyte can alter the structure, the state of the protein,

causing it to aggregate or dissociate, thereby changing its properties.

However, the interaction between the solvents protein and the polyelectrolyte with the same net charge is not fully understood.

The main technique which I use here is AUC.

Because all of you are the experts in this field, I will not spend time to explain the principle of this technique.

The AUC ultra-centrifuge is essential for the preparation of ultra-centrifuge with optics.

Historically, the analytical ultra-centrifuge emerged before the preparation of ultra-centrifuge.

For UV-based absorbent optics, the instrument measures the absorbance of the solute with respect to position and time.

The concentration change with time can be described by the LAM equation.

By fitting the data and combining it with the Sveberg equation and Einstein-Stokes equation,

several parameters such as sedimentation coefficient, diffusion coefficient, hydrodynamic radius, frictional ratio, molar mass can be obtained.

First, we synthesize three diprocopolymer with different lengths of polystyrene sulfonate using the Raft polymerization.

Within the measurement of the sedimentation coefficient distribution of these three diprocopolymer,

we can see the sedimentation coefficient increase with the increase in the length of the PSS.

The PEG is used to reduce the formation of insoluble complexes.

We then measure the UV absorbance spectra of these three diprocopolymer.

You can see here there is a characteristic peak at 340 nanometers, originated from the thi-carbonyl group here.

Based on the extinction coefficient at the two wavelengths, 340 nanometers and 280 nanometers,

we can calculate the absorbed diprocopolymer on each 11S molecule.

Then we mix the glycine or 11S molecule with different concentrations of the diprocopolymer.

This is the result. You can see with different concentrations of this diprocopolymer,

the polymerization degree of PSS is 33.

Here is a single peak for different concentrations.

The area under this peak remains constant, which means that there is no insoluble complex formed.

The sedimentation coefficient increases with the increase in concentration.

We know that the sedimentation coefficient is influenced by the molar mass and the size of the complexes.

Assuming that the size of the complexes didn't change,

the sedimentation coefficient is determined by the molar mass of the complexes.

This tells us that some absorption of the diprocopolymer on the 11S happens.

Then we measure the sedimentation velocity experiment at 340 nanometers.