Calculate protein molecular mass

Honestly, I want to share my probblem in Lab. to you all and hopping that I can get the answer immediately.

Is there anyone who know how to calculate protein size (kDa) exactly?

I have a data of L-arabinose isomerase amino acid sequence which has to be checked by using SDS-PAGE method. But, it will not give any benefit if I don’t know the size of the protein that I’ve investigated.

As we know, to judge whether our gene over-expression is success or not we should get the band at the appropriate position in acrylamide gel. The position of the band tell us about its protein molecular mass (kilo Dalton or kDa). If we know how kDa’s our protein are (ex. 55 kDa), then we could judge whether our over-expression is success or not. It is claimed succes if the band lay between 43 and 66.2 kDa (Picture 1). Conversly, it is claimed fail if the band doesn’t appear or appear in other position.

ACAI molecular mass (55 kDa) checked by SDS-PAGE (source: Cheng et al., 2010)

And the problem is, I DON’T KNOW HOW kDa’s MY PROTEIN ARE?? So, how could I judge the result??

–well, I tried to calculate it manually by using this formula:

Suggestion I.

average amino acid molecular mass : 11.0 kDa

number of my amino acid in vector: 534

So, my protein mass (rudely) would be: 534 x 11.0 = 58.74 kDa

But, is it the exact mass?? To be honest, I my self doubt with it. So, I try to find another method which is more valid and trustable. And, this is it: I’ve found the trustable method to calculate protein molecular mass.

Suggestion  II. (More valid, trust me!! *-^!!)

Use an online program called ‘protparam

Enter a Swiss-Prot/TrEMBL accession number,  or

Paste your own sequence in the box availabled –> compute parameters


Result of my protein molecular mass calculation

Pay attention to  the words “Molecular weight”. Those shows in Dalton (Da). You may convert it to kDa (1 kDa=1000 Da).

Well, finally I got the valid mass now. If it worthfull for you, you may follow my suggestion.

Have a good work!!!


My protein is: local strain Geobacillus stearothermophilus L-arabinose isomerase or GSAI

Total number of amino acid sequence I put to calculate the mass manually are the AA expressed by araA inserted in pET-21b.


21 Komentar

  1. If you would like to improve your knowledge just keep visiting this web site and be updated with the most
    up-to-date news posted here.

  2. Good post! We will be linking to this particularly great post on our site.
    Keep up the good writing.

  3. Hello there, just became alert to your blog through Google, and found
    that it is really informative. I’m gonna watch out for brussels. I will be grateful if you continue this in future. A lot of people will be benefited from your writing. Cheers!

  4. Very energetic post, I enjoyed that a lot. Will there be a part 2?

  5. “Calculate protein molecular mass Neoaisyah” was really compelling and helpful!
    In todays world that’s very hard to carry out. Regards, Jaqueline

  6. Toothpick: it allows the removal of large debris accumulated
    in the interdental spaces is often inaccessible to the bristles of the brush.
    Dentists recommend brushing your teeth for at least two minutes
    each time you brush. This is now Steve Ballmer’s Microsoft, and it seems quite different from the giant built by Bill Gates.

  7. Like many newcomers to comes up oft among citizenry who
    Feature held Medigap Plans for a retentive prison term.
    some states, such as California, A through L consists of dissimilar sets
    of extra and basic benefits.

  8. I love your blog.. very nice colors & theme. Did you make this website yourself or
    did you hire someone to do it for you? Plz answer back as I’m looking to construct my own blog and would like to find out where u got this from. many thanks

  9. While in town, be sure that you have planned at the very least trying,
    and we had no trouble pairing them with our setup. Along with kilometer
    customers kilometer connected with shoreline along with
    a rental car will allow you to rent Mercedes at cheap affordable price rates
    and get an Essex Wedding paphos car hire.

  10. I am really loving the theme/design of your website. Do you ever run into any web
    browser compatibility problems? A small number of my blog visitors have complained about my website not operating correctly in
    Explorer but looks great in Safari. Do you have any advice to help fix this problem?

  11. What’s up colleagues, its fantastic paragraph regarding cultureand completely explained, keep it up all the time.

  12. Very good info. Lucky me I found your website by chance (stumbleupon).

    I have saved it for later!

  13. I every time emailed this web site post page to all my associates, since if like to read it next
    my friends will too.

  14. Hey! It seems as though we both have a interest for the same thing.
    Your blog, “Calculate protein molecular mass | Neoaisyah” and mine are very similar.
    Have you ever thought about writing a guest post for a
    similar website? It will unquestionably help gain exposure to
    your blog (my site recieves a lot of traffic). If you are interested, contact me at: Thank you

  15. What’s up to every one, it’s truly a fastidious for me to pay a visit
    this website, it consists of useful Information.

  16. Currently it seems like Drupal is the top blogging platform
    available right now. (from what I’ve read) Is that what you are using on your blog?

  17. Would you mind if I quote a couple of your articles
    or blog posts as long as I provide credit and sources returning to your website:
    I will aslo be certain to give you the proper anchortext link
    using your website title: Calculate protein molecular mass | Neoaisyah.
    Be sure to let me know if this is okay with you. With thanks

  18. Hello, I think your site might be having browser compatibility issues.
    When I look at your blog site in Safari, it looks fine but when opening in Internet Explorer, it has some overlapping.
    I just wanted to give you a quick heads up! Other then
    that, fantastic blog!

  19. It’s remarkable to visit this web site and reading the views of all colleagues on the topic of this article, while I am also keen of getting familiarity.

  20. Hello, Neat post. There is a problem with your site in internet explorer, might test
    this? IE still is the marketplace chief and a good component to other people will pass over your wonderful writing due to this problem.

  21. Very nice article. I absolutely appreciate this website.
    Keep it up!

Comments RSS TrackBack Identifier URI

Tinggalkan Balasan

Isikan data di bawah atau klik salah satu ikon untuk log in:


You are commenting using your account. Logout /  Ubah )

Foto Google+

You are commenting using your Google+ account. Logout /  Ubah )

Gambar Twitter

You are commenting using your Twitter account. Logout /  Ubah )

Foto Facebook

You are commenting using your Facebook account. Logout /  Ubah )


Connecting to %s