Chemical-Structural Identification of Crude Gelatin from Jellyfish (Stomolophus meleagris) and Evaluation of Its Potential Biological Activity
, Santiago P. Aubourg 3, Jesús Aarón Salazar-Leyva 4, Francisco RodrÃguez-Felix 1 and Josafat Marina Ezquerra-Brauer 1,*
Round 1
Reviewer 1 Report
Dear Author(s),
Thank you for submitting your manuscript on the scientific analysis of proteins using crude gelatin extracted and prepared from brown cannonball jellyfish. We appreciate the effort put into the research and the opportunity to review your work.
However, we have some concerns regarding the manuscript's preparation that we would like to address. The main issue we encountered was the inconsistency in the naming and usage of the samples throughout the manuscript. The use of various terms such as "protein extract," "gelatin powder," "freeze-dried protein," "dried sample," and "sample" may lead to a false impression that the authors have succeeded in elucidating the brown cannonball jellyfish protein in general when nothing more than its properties as a crude gelatin purification product can be determined in this study.
Therefore, we suggest using the name "crude gelatin sample" consistently throughout the manuscript, and the last part of the introduction should explicitly state that the analyte was "crude gelatin" and not "protein extract."
In addition, the authors have omitted several essential explanations in the method section by citing previous papers. Specifically, the solubilization method of the "crude gelatin sample" and the HPLC conditions for Amino Acid Analysis, including derivatization of labeled substances and types of columns, were not adequately explained. The minimum information required to reproduce the experiment should be described in detail.
Furthermore, we note that many results, such as crude protein, amino acid composition, and SDS-PAGE analysis, suggest that the main component of this natural gelatin purification is gelatin. Therefore, we recommend emphasizing the large amide I and amide II peaks characteristic of gelatin in the FT-IR results. Although proteins other than collagen are detected in the proteome results, this should not overly suggest the possibility of biological activity properties.
We hope you find our comments and suggestions helpful and can incorporate them into your manuscript's revision. Thank you again for the opportunity to review your work.
Author Response
Response to Reviewer 1 Comments
Thank you for your suggestions and comments. In the main document, the substantive amendments are indicated in blue. We respond to each comment in the following paragraphs:
Point 1: Regarding " The use of various terms such as "protein extract," "gelatin powder," "freeze-dried protein," "dried sample," and "sample" may lead to a false impression that the authors have succeeded in elucidating the brown cannonball jellyfish protein in general when nothing more than its properties as a crude gelatin purification product can be determined in this study.
Therefore, we suggest using the name "crude gelatin sample" consistently throughout the manuscript, and the last part of the introduction should explicitly state that the analyte was "crude gelatin" and not "protein extract."
Response 1: Thank you for your suggestion. We agree with you. Throughout the document we change the terms “protein extracts”, “ gelatin powder”, freeze-dried protein”, “dried sample”, and “sample” to “crude gelatin sample” and in the introduction, the term “protein extract” was modified by “crude gelatin” as well as in the title.
Point 2: In addition, the authors have omitted several essential explanations in the method section by citing previous papers. Specifically, the solubilization method of the "crude gelatin sample" and the HPLC conditions for Amino Acid Analysis, including derivatization of labeled substances and types of columns, were not adequately explained. The minimum information required to reproduce the experiment should be described in detail.
Response 2: Thank you for your observation. We agree with you. The amino acid analysis section (2.4.2) was completely changed. Please see L 157-180.
Point 3: Furthermore, we note that many results, such as crude protein, amino acid composition, and SDS-PAGE analysis, suggest that the main component of this natural gelatin purification is gelatin. Therefore, we recommend emphasizing the large amide I and amide II peaks characteristic of gelatin in the FT-IR results. Although proteins other than collagen are detected in the proteome results, this should not overly suggest the possibility of biological activity properties.
Response 3: Thank you a lot for your comments and suggestion. We agree completely agree with you. More discussion on FT-IR was added. Please see L401 to 405.
Reviewer 2 Report
The authors present an interesting manuscript in terms of maximizing the nutraceutical value of jellyfish. In my understanding, the paper is well written and only minor revisions are recommended.
Line 14: the number associated with this affiliation should be 4 instead of 3
Line 135: the number of section should be 2.3.2. instead of 2.3.3.
Line 171: replace 2.4.3. with 2.4.5.
Lines 214-258: in Materials and Methods the authors reported that “in vitro antioxidant activities for the produced gelatin powder were evaluated using four spectrophotometric assays: (ABTS·+), (FRAP), (ORAC), (AAPH), however not results have been provided for FRAP.
Line 282: replace table 2 with table 1
Line 306-309: a protein value of 10.49 ± 0.183 g of this study could be comparable with 5.5 g/100 g of Cyanea nozakii Kishinouye?
Lines 323-325: comparing the amino acid composition of S. meleagris with other marine organisms high values of GLY, ARG and PRO have been also recently reported for deep water rose shrimps: https://www.frontiersin.org/articles/10.3389/fnut.2022.955216/full
Line 425: replace 3.3.6. with 3.3.7.
Author Response
Response to Reviewer 2 Comments
Thank you for your suggestions and comments. In the main document, the substantive amendments are indicated in blue. We respond to each comment in the following paragraphs:
Point 1: The authors present an interesting manuscript in terms of maximizing the nutraceutical value of jellyfish. In my understanding, the paper is well written and only minor revisions are recommended.
Response 1: Thank you for your comments, we appreciate it a lot.
Point 2: Line 14: the number associated with this affiliation should be 4 instead of 3
Response 2: Thank you for your observation. Done
Point 3: Line 135: the number of section should be 2.3.2. instead of 2.3.3.
Response 3: Thank you for your observation. Done
Point 4: Line 171: replace 2.4.3. with 2.4.5.
Response 4: Thank you for your observation. Done
Point 5: Lines 214-258: in Materials and Methods the authors reported that “in vitro antioxidant activities for the produced gelatin powder were evaluated using four spectrophotometric assays: (ABTS·+), (FRAP), (ORAC), (AAPH), however not results have been provided for FRAP.
Response 5: Thank you a lot for your comments and observation. Sorry for this failure, please accept our apologies. The crude gelatin sample analyzed did not show the ability to reduce ferric-tripyridyltriazine (FeIII-TPTZ) and form ferrous-tripyridyltriazine (FeII-TPTZ). We added the following phrase (Please see L 255-257).
“Although the jellyfish crude gelatin samples showed the ability to quench radicals, they did not show the ability to reduce ferric-tripyridyltriazine (FeIII-TPTZ) and forming ferrous-tripyridyltriazine (FeII-TPTZ).”
Point 6: Line 282: replace table 2 with table 1
Response 6: Thank you for your observation. Done
Point 7: Line 306-309: a protein value of 10.49 ± 0.183 g of this study could be comparable with 5.5 g/100 g of Cyanea nozakii Kishinouye?
Response 7: Thank you for your observation. Agree with you. The phrase was modified as follows (please see L 335-336):
“This result is higher than other previously reported values, such as in Stomolophus meleagris (7.5 g/100 g) [46] and for Cyanea nozakii Kishinouye (5.5 g/100 g) [9].”
Point 8: Lines 323-325: comparing the amino acid composition of S. meleagris with other marine organisms high values of GLY, ARG and PRO have been also recently reported for deep water rose shrimps: https://www.frontiersin.org/articles/10.3389/fnut.2022.955216/full
Response 8: Thank you for your suggestion. Agree with you. The following phrase was added (please see L 357-358):
“The amino acid composition trends (high concentration of Gly, Arg, and Pro) is comparable to another marine organism, deep water rose shrimps [50].”
Point 9: Line 425: replace 3.3.6. with 3.3.7.
Response 9: Thank you for your observation. Done
Reviewer 3 Report
The manuscript titled "Chemical-structural identification of protein from jellyfish 2 (Stomolophus meleagris) and evaluation of its potential biological activity" is an impressive contribution to the field of food science and nutrition. The study presents an innovative approach to identifying bioactive compounds in jellyfish and successfully demonstrates the antioxidant and antimutagenic properties of the protein extracts, which were identified as containing collagen, tubulins, and histones through proteomic analysis. The manuscript is well-organized and easy to follow, with sufficient details of the experimental procedures to facilitate reproducibility by other researchers. The use of a proteomic approach to identify the specific proteins present in the jellyfish extracts is particularly noteworthy and provides valuable insights into the bioactivities of these proteins. The findings of the study are highly relevant and have the potential to lead to the development of novel applications of jellyfish protein extracts in the food industry. Overall, this manuscript deserves to be published in the journal of Fishes.
The manuscript's English language quality is good, characterized by the use of proper scientific terminology, clear and concise writing, and grammatical accuracy.
Author Response
Thank you for your comments we appreciate it a lot.
