Are Catalytic Antibodies Evidence for Evolution of New Function?

One of the common claims heard in these debates is that there is a low probability of random sequence having function. Catalytic antibodies may offer a good way of testing this claim.

During embryonic development, B-cells go through a process where segments of DNA are randomly shuffled and stitched together (VDJ recombination) to make the variable regions of antibodies, the sections of the antibody that are responsible for sticking to bacteria, viruses, and other antigens. Each B-cell lineage has just one combination of this shuffled DNA, and there are about 100 million B-cell lineages in each human being and in other mammalian species [NOTE: I’m not sure how this may or may not work in more distantly related vertebrate species, so I am sticking with mammals].

So what are the chances that these randomly shuffled bits of DNA will have enzyme activity? As it turns out, antibodies with enzyme function are relatively common. The following review article discusses several different catalytic antibodies, one of which is pretty crazy:

The existence of catalytic antibodies tells me that evolving function is relatively easy. Shuffling a few bits of DNA around produces many different and specific catalytic enzymes, some of which include beta-lactamase activity which some ID supporters have argued is almost impossible to evolve.

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A random sequence is likely to fold on itself isn’t it? So there you have it, they probably all have a function.

Folding isn’t what we mean by function.

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I would probably use “having” or “possessing” instead of “acquiring”.

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The Scripps Institute is big into protein research, so it is instructive that they are looking into catalytic antibodies as a source of novel proteins.

And in any case, isn’t necessarily required for function. Some intrinsically disordered proteins have functional motifs even when the protein doesn’t have a well-defined shape.

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I agree. @Mung, do you get this important point, or have you been bamboozled by DI water-muddying propaganda?

Put another way, folding and unfolding is a much more active process than you’ve been led to believe. It goes both ways and is relevant to both regulation and disease.

Only you know what you mean by function. People seem to have a wide range of what they are willing to accept as function. I think that the function of biomolecules is to fold, because that is what they do naturally.

Some of them do, and occasionally some of them don’t. Both types are found in living organisms, having activities that aid the organism in survival and reproduction.

@Mercer, I don’t much care for people who think they can read minds and who think they somehow have access to what I know. How about you?

In this specific topic, function is defined as enzymatic activity. This is the definition in scientific jargon:

Me neither, which is why I asked instead of assuming. Based on what you wrote:

I hypothesized that you have been bamboozled, so I asked what you know. No mind reading.
Your response strongly suggests bamboozlement:

Given the context clearly provided in the title, function is catalysis.

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Ironically I think Mung was actually trying to saddle you with the view that if it folds, it’s functional. The implication being that you’re just going to arbitrarily define function in a way that depends on a measure that shows most proteins are functional even if they really aren’t.

Here’s what you wrote:

You don’t know what I have been led to believe. You don’t know what I do or do not know about folding of biological macromolecules or how I have come to know what i know. You are pretending to have knowledge that you lack.

Mung, is that true? If so, I’m shocked.

I wrote that after you confirmed your bamboozlement. Three times you’ve conflated folding with function. It’s just wrong.

Are you sure he is bamboozled? This also fits his pattern of trying to score word parsing points to demonstrate (to whom?) how clever he is.

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