Saturday, April 24, 2021

Creation Moment 4/25/2021 - Lesson from XCL1

Thank you for making me so wonderfully complex!
Your workmanship is marvelous... Psalm 139:14 NLT

Below is an article where darwinians think this evolved---BUT PAY CLOSE ATTENTION---what they actually find is a well DESIGNED SYSTEM that, even when it breaks down by losing information that pre-exists, has the ability to try and adjust to the breaks....and some of what is thought of as breaking down may actually be part of the DESIGN for a purpose and actually isn't malfunctioning....regardless they label this as "NOT AN ACCIDENT".

"Classically, a protein is imagined as a chain of amino acids that folds into a single stable configuration... But in the last few years, biophysicists have learned how numerous and extraordinary the exceptions to that rule are—including some two-faced proteins that can refold as needed in an instant.

First came the discovery of a special class of fold-switching proteins that have more than one stable conformation and can perform two different functions

The Wisconsin researchers decided to learn about metamorphic

proteins by looking at XCL1 more closely. Of the 46 chemokine proteins in humans, XCL1 is the only one that exhibits metamorphic switching. The others are stabilized by strong disulfide bonds that lock their protein molecules into a stable fold. But of XCL1, one of the disulfide bonds was lost, allowing a second conformation to emerge.

To reconstruct how that happened, the researchers used bioinformatics to infer the ancestral sequences for about 550 chemokines in today’s animals. Acacia Dishman, a graduate student, inserted the inferred DNA sequences into bacteria to resurrect the ancestral proteins. She then purified them, measured their biophysical properties and checked their structures with nuclear magnetic resonance for the distinctive “fingerprints” of the protein folds.

Q: But why would metamorphosis be better than having two specialized proteins? 
A: If a single protein can do double duty, it spares the cell from transcribing, translating and maintaining more than one gene. 
--But the more compelling advantage may be that the protein’s ability to transform may give the body a more dynamic way to control its defenses against bacteria.
 
Because XCL1 can adopt its two folded forms with equal probability, it can switch between them faster than once per second
---But changes in the temperature 
---or salt concentration 
---or the introduction of binding partners can change that equilibrium. 
For example, around microbial pathogens, more of the XCL1 proteins get stuck in the conformation that interacts with the microbial membranes, shifting the balance toward that fold. Elsewhere in the body, the protein can adopt the other fold more often and bind to the receptors on white blood cells to mobilize them. 
 
Dishman found that the oldest ancestor had a single stable fold, the
one common to all the chemokines. In proteins from a little later in the reconstructed sequence, she detected two fingerprints, one for the ancestral fold but also one for a newer fold, although the new fold remained rare. 
Surprisingly, just a little later in the sequence, proteins showed the opposite: They were mainly folded in the new conformation and only rarely in the ancestral conformation. Finally, in the modern XCL1, the two conformations were about equal, Dishman found.
 
The fact that the ancestors exhibited the two folds unevenly while the modern XCL1 exhibits both in equal proportion strongly suggests that the switching property is not an accident or an artifact. It’s something that must have been beneficial and improved the fitness of the organism, ...,” said Brian Volkman." Nautilus